diff --git a/.env.template b/.env.template
deleted file mode 100644
index e1b749c..0000000
--- a/.env.template
+++ /dev/null
@@ -1 +0,0 @@
-PHP_VERSION=8.3
diff --git a/dev/.env.template b/dev/.env.template
new file mode 100644
index 0000000..c45cb9b
--- /dev/null
+++ b/dev/.env.template
@@ -0,0 +1,6 @@
+PHP_VERSION=8.3
+XDEBUG_PORT=9019
+XDEBUG_MODE=debug,develop
+XDEBUG_IDE_KEY=PHPSTORM
+XDEBUG_IDE_CONFIG=serverName=Docker
+EXTENSIONS_DISABLE=""
diff --git a/dev/init.sh b/dev/init.sh
new file mode 100644
index 0000000..ce7f9bf
--- /dev/null
+++ b/dev/init.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+[ -f ./.env ] || cp ./dev/.env.template ./.env
+echo ".env ok"
diff --git a/dev/php.ini b/dev/php.ini
new file mode 100644
index 0000000..9976163
--- /dev/null
+++ b/dev/php.ini
@@ -0,0 +1,5 @@
+zend_extension=xdebug.so
+xdebug.mode=debug
+xdebug.client_port=9019
+xdebug.idekey=PHPSTORM
+xdebug.client_host=host.docker.internal
diff --git a/docker-compose.yml b/docker-compose.yml
index 0069de9..43c8174 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,14 +2,26 @@ version: '3.8'
 
 services:
   php:
-    build:
-      context: .
-      args:
-        - PHP_VERSION=${PHP_VERSION}
-    container_name: php
+    image: wodby/php:${PHP_VERSION}
+    working_dir: /srv/web
+    container_name: templater-php
     volumes:
       - .:/srv/web
+      - ./dev/php.ini:/usr/local/etc/php/conf.d/z-php-sp-overrides.ini
     environment:
-      - XDEBUG_MODE=off
+      XDEBUG_CONFIG: client_host=host.docker.internal
+      XDEBUG_MODE: $XDEBUG_MODE
+      PHP_XDEBUG: 1
+      PHP_XDEBUG_DEFAULT_ENABLE: 1
+      PHP_IDE_CONFIG: $XDEBUG_IDE_CONFIG
+      PHP_XDEBUG_CLIENT_PORT: $XDEBUG_PORT
+      PHP_XDEBUG_IDEKEY: $XDEBUG_IDE_KEY
+      PHP_EXTENSIONS_DISABLE: $EXTENSIONS_DISABLE
     ports:
       - "9000:9000"
+    networks:
+        - itron-network
+
+networks:
+  itron-network:
+    driver: bridge
diff --git a/dockerfile b/dockerfile
deleted file mode 100644
index 8421b68..0000000
--- a/dockerfile
+++ /dev/null
@@ -1,21 +0,0 @@
-ARG PHP_VERSION
-
-FROM php:${PHP_VERSION}-fpm
-
-RUN apt-get update && apt-get install -y \
-    git \
-    unzip \
-    zip \
-    && docker-php-ext-install pdo pdo_mysql
-
-COPY --from=composer:latest /usr/bin/composer /usr/bin/composer
-
-WORKDIR /srv/web
-
-COPY . .
-
-RUN chown -R www-data:www-data /srv/web
-
-EXPOSE 9000
-
-CMD ["php-fpm"]
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..fdb87f3
--- /dev/null
+++ b/makefile
@@ -0,0 +1,18 @@
+init:
+	bash ./dev/init.sh
+
+docker.up:
+	docker-compose -p itron-templater up -d
+
+docker.down:
+	docker-compose -p itron-templater down
+
+docker.build.php:
+	docker-compose -p itron-templater up -d --build php
+
+connect.php:
+	docker-compose -p itron-templater exec php bash
+
+tests.php.run:
+	docker-compose -p itron-templater exec php vendor/bin/phpunit
+
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index c05e186..ab37037 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -9,6 +9,10 @@
 	>
 	<php>
 		<const name="DOING_TESTS" value="1" />
+
+		<ini name="xdebug.mode" value="debug"/>
+		<ini name="xdebug.client_port" value="9019"/>
+		<ini name="xdebug.idekey" value="PHPSTORM"/>
 	</php>
 	<testsuites>
 		<testsuite name="WP_Lock concurrency mutexes for WordPress test suite">
diff --git a/src/Templater.php b/src/Templater.php
index e97a44d..8b64cba 100644
--- a/src/Templater.php
+++ b/src/Templater.php
@@ -137,16 +137,18 @@ private function get_repeaters( $subject ) {
 			'clear'   => [],
 		];
 
-		foreach ( $m['content'] as $found ):
+		foreach ( $m['content'] as $index => $found ):
 			$inner = $this->get_repeaters( $found );
 			if ( is_array( $inner ) ) :
 				$result['tag']     = array_merge( $result['tag'], $inner['result']['tag'] );
 				$result['content'] = array_merge( $result['content'], $inner['result']['content'] );
-				$result['clear']   = array_merge( $result['clear'],
-					[ str_replace( $inner['data'][0], '', $found ) ],
-					$inner['result']['clear'] );
+				$result['clear']   = array_merge(
+					$result['clear'],
+					[ $m['tag'][$index] => str_replace( $inner['data'][0], '', $found ) ],
+					$inner['result']['clear'],
+				);
 			else :
-				$result['clear'] [] = $found;
+				$result['clear'][ $m['tag'][$index] ] = $found;
 			endif;
 		endforeach;
 
@@ -167,14 +169,15 @@ private function get_repeaters_data( $data, $context ) {
 							}
 						endforeach;
 					}
-					$substr .= ( false !== $key = array_search( $row['tag'], $context['result']['tag'] ) ) ?
-						$this->format( $context['result']['clear'][ $key ], $content ) :
-						( is_array( $content ) ? implode( '', $content ) : $content );
+
+					$substr .= $this->format(
+						$context['result']['clear'][ $context['result']['tag'][ array_search( $row['tag'], $context['result']['tag'] ) ] ],
+						$content
+					);
 				elseif ( ! empty( $content ) ) :
 					$substr .= ( is_array( $content ) ? implode( '', $content ) : $content );
 				elseif ( ! empty( $row['tag'] ) ) :
-					$substr .= ( false !== $key = array_search( $row['tag'], $context['result']['tag'] ) ) ?
-						$context['result']['clear'][ $key ] : '';
+					$substr .= $context['result']['clear'][ $context['result']['tag'][ array_search( $row['tag'], $context['result']['tag'] ) ] ];
 				endif;
 			endforeach;
 			$out = $substr;
diff --git a/tests/TemplaterTest.php b/tests/TemplaterTest.php
index 523109f..24c2716 100644
--- a/tests/TemplaterTest.php
+++ b/tests/TemplaterTest.php
@@ -3,6 +3,8 @@
 use iTRON\Templater\Templater;
 use PHPUnit\Framework\TestCase;
 
+require_once 'inc/functions.php';
+
 class TemplaterTest extends TestCase {
 
 	public function testRender() {
@@ -75,12 +77,14 @@ public function testRender() {
 
 		$expected = <<<EXPECTED
 <div class="classname">
-	<div class="tag1">CONTENT1</div><div class="tag1">CONTENT1.2</div><div class="tag1">CONTENT1.3</div>
+	<div class="tag1">CONTENT1</div>
+	<div class="tag1">CONTENT1.2</div>
+	<div class="tag1">CONTENT1.3</div>
 	<div class="tag2">CONTENT2</div>
 </div>
 EXPECTED;
 
-		$this->assertEquals( $expected, $result );
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
 
 		/**
 		 * Template with a preselected value.
@@ -107,13 +111,15 @@ public function testRender() {
 
 		$expected = <<<EXPECTED
 <div class="classname">
-	<div class="tag1">CONTENT1</div><div class="tag1">CONTENT1.2</div><div class="tag1">CONTENT1.3</div>
+	<div class="tag1">CONTENT1</div>
+	<div class="tag1">CONTENT1.2</div>
+	<div class="tag1">CONTENT1.3</div>
 	<div class="tag2">CONTENT2</div>
 	value2
 </div>
 EXPECTED;
 
-		$this->assertEquals( $expected, $result );
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
 
 		/**
 		 * The same test with a wrong index.
@@ -132,22 +138,69 @@ public function testRender() {
 
 		$expected = <<<EXPECTED
 <div class="classname">
-	<div class="tag1">CONTENT1</div><div class="tag1">CONTENT1.2</div><div class="tag1">CONTENT1.3</div>
+	<div class="tag1">CONTENT1</div>
+	<div class="tag1">CONTENT1.2</div>
+	<div class="tag1">CONTENT1.3</div>
 	<div class="tag2">CONTENT2</div>
 	value1
 </div>
 EXPECTED;
 
-		$this->assertEquals( $expected, $result );
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
+	}
+
+	public function testNestedRepeaters() {
+		$templater = new Templater();
+
+		/**
+		 * Template with several tags.
+		 */
+		$tpl = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]<div class="sub-list">%s</div>[[/list-item]]
+</div>
+
+[[logo]]<div class="logo">%s</div>[[/logo]]
+[[text]]<div class="text">%s</div>[[/text]]
+TEMPLATE;
+
+		$result = $templater->render( $tpl, [
+			[
+				[
+					'tag'     => 'list-item',
+					'content' => [
+						[
+							[ 'tag' => 'logo', 'content' => 'LOGO1' ],
+							[ 'tag' => 'text', 'content' => 'TEXT1' ],
+						]
+					],
+				],
+			],
+		] );
+
+		$expected = <<<EXPECTED
+<div class="list">
+  <div class="sub-list">
+  	<div class="logo">LOGO1</div>
+  	<div class="text">TEXT1</div>
+  </div>
+</div>
+EXPECTED;
+
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
 
 		/**
 		 * Template with nested repeaters.
 		 */
 		$tpl = <<<TEMPLATE
 <div class="classname">
-	%s[[tag1]]<div class="tag1">
-		%s[[tag2]]<div class="tag2">%s</div>[[/tag2]]
-	</div>[[/tag1]]
+	%s
+	[[tag1]]
+	<div class="tag1">
+		%s
+		[[tag2]]<div class="tag2">%s</div>[[/tag2]]
+	</div>
+	[[/tag1]]
 </div>
 TEMPLATE;
 
@@ -173,6 +226,327 @@ public function testRender() {
 EXPECTED;
 
 
-		$this->assertEquals( $expected, $result );
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
+
+		/**
+		 * Tests template with several nested tags.
+		 */
+		$tpl = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+  <div class="sub-list">%s</div>
+  
+	[[logo]]<div class="logo">%s</div>[[/logo]]
+	[[text]]<div class="text">%s</div>[[/text]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+
+		$result = $templater->render( $tpl, [
+			[
+				[
+					'tag'     => 'list-item',
+					'content' => [
+						[
+							[ 'tag' => 'logo', 'content' => 'LOGO1' ],
+							[ 'tag' => 'text', 'content' => 'TEXT1' ],
+						]
+					],
+				],
+			],
+		] );
+
+		$expected = <<<EXPECTED
+<div class="list">
+  <div class="sub-list">
+  	<div class="logo">LOGO1</div>
+  	<div class="text">TEXT1</div>
+  </div>
+</div>
+EXPECTED;
+
+
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
+
+		$tpl = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+		%s
+  
+	[[logo]]
+	<div class="logo">
+		%s
+	</div>
+	[[/logo]]
+	[[text]]<div class="text">%s</div>[[/text]]
+	[[img]]<img src="%s" alt=""/>[[/img]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+
+		$data = [
+			[
+				[
+					'tag'     => 'list-item',
+					'content' => [
+						[
+							[
+								'tag'     => 'logo',
+								'content' => [
+									[
+										[ 'tag' => 'img', 'content' => 'localhost//image1.jpg' ],
+									]
+								]
+							],
+							[ 'tag' => 'text', 'content' => 'TEXT1' ],
+						]
+					],
+				],
+			],
+		];
+
+		$result = $templater->render( $tpl, $data );
+
+		$expected = <<<EXPECTED
+<div class="list">
+  <div class="logo">
+  	<img src="localhost//image1.jpg" alt=""/>
+  </div>
+  <div class="text">TEXT1</div>
+</div>
+EXPECTED;
+
+
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
+
+		/**
+		 * The same test, but with a deeper nesting.
+		 */
+
+		$tpl = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+		%s
+  
+	[[logo]]
+	<div class="logo">
+		%s
+		[[img]]<img src="%s" alt=""/>[[/img]]
+	</div>
+	[[/logo]]
+	[[text]]<div class="text">%s</div>[[/text]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+
+		$result = $templater->render( $tpl, $data );
+		// This fails.
+		$this->assertEquals( remove_spaces( $expected ), remove_spaces( $result ) );
+	}
+
+	public function testGetRepeaters() {
+		$templater = new Templater();
+		$method    = new ReflectionMethod( Templater::class, 'get_repeaters' );
+		$method->setAccessible( true );
+
+		/**
+		 * Simple template with nested repeaters.
+		 */
+		$tpl = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+    %s[[logo]]<div class="logo">%s</div>[[/logo]][[text]]<div class="text">%s</div>[[/text]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+
+		$result = $method->invoke( $templater, $tpl );
+
+		$expected = [
+			'result' => [
+				'clear' => [
+					'list-item' => '%s',
+					'logo'      => '<div class="logo">%s</div>',
+					'text'      => '<div class="text">%s</div>'
+				],
+
+				'content' => [
+					'%s[[logo]]<div class="logo">%s</div>[[/logo]][[text]]<div class="text">%s</div>[[/text]]',
+					'<div class="logo">%s</div>',
+					'<div class="text">%s</div>'
+				],
+
+				'tag' => [
+					'list-item',
+					'logo',
+					'text',
+				],
+			],
+		];
+
+		$this->assertEquals(
+			remove_spaces_recursively( $expected['result'] ),
+			remove_spaces_recursively( $result['result'] )
+		);
+
+		/**
+		 * Deep nested.
+		 */
+		$tpl = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+		%s
+  
+	[[logo]]
+	<div class="logo">
+		%s
+	</div>
+	[[/logo]]
+	[[text]]<div class="text">%s</div>[[/text]]
+	[[img]]<img src="%s" alt=""/>[[/img]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+
+		$result   = $method->invoke( $templater, $tpl );
+		$expected = [
+			'result' => [
+				'clear' => [
+					'list-item' => '%s',
+					'logo'      => '<div class="logo">%s</div>',
+					'text'      => '<div class="text">%s</div>',
+					'img'       => '<img src="%s" alt=""/>',
+				],
+
+				'content' => [
+					'%s[[logo]]<div class="logo">%s</div>[[/logo]][[text]]<div class="text">%s</div>[[/text]][[img]]<img src="%s" alt=""/>[[/img]]',
+					'<div class="logo">%s</div>',
+					'<div class="text">%s</div>',
+					'<img src="%s" alt=""/>',
+				],
+
+				'tag' => [
+					'list-item',
+					'logo',
+					'text',
+					'img',
+				],
+			],
+		];
+
+		$this->assertEquals(
+			remove_spaces_recursively( $expected['result'] ),
+			remove_spaces_recursively( $result['result'] )
+		);
+
+		/**
+		 * The same, but with a deeper nesting.
+		 */
+		$tpl      = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+		%s
+  
+	[[logo]]
+	<div class="logo">
+		%s
+		[[img]]<img src="%s" alt=""/>[[/img]]
+	</div>
+	[[/logo]]
+	[[text]]<div class="text">%s</div>[[/text]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+		$expected = [
+			'result' => [
+				'clear' => [
+					'list-item' => '%s',
+					'logo'      => '<div class="logo">%s</div>',
+					'text'      => '<div class="text">%s</div>',
+					'img'       => '<img src="%s" alt=""/>',
+				],
+
+				'content' => [
+					'%s[[logo]]<div class="logo">%s[[img]]<img src="%s" alt=""/>[[/img]]</div>[[/logo]][[text]]<div class="text">%s</div>[[/text]]',
+					'<div class="logo">%s[[img]]<img src="%s" alt=""/>[[/img]]</div>',
+					'<div class="text">%s</div>',
+					'<img src="%s" alt=""/>',
+				],
+
+				'tag' => [
+					'list-item',
+					'logo',
+					'text',
+					'img',
+				],
+			],
+		];
+
+		$result = $method->invoke( $templater, $tpl );
+		// This fails.
+		$this->assertEquals(
+			remove_spaces_recursively( $expected['result'] ),
+			remove_spaces_recursively( $result['result'] )
+		);
+	}
+
+	public function testDeepNested_repeaters_parser() {
+		$templater = new Templater();
+		$method    = new ReflectionMethod( Templater::class, 'get_repeaters' );
+		$method->setAccessible( true );
+
+		/**
+		 * The same, but with a deeper nesting.
+		 */
+		$tpl      = <<<TEMPLATE
+<div class="list">
+  %s[[list-item]]
+		%s
+  
+	[[logo]]
+	<div class="logo">
+		%s
+		[[img]]<img src="%s" alt=""/>[[/img]]
+		[[caption]]<span class="caption">%s</span>[[/caption]]
+	</div>
+	[[/logo]]
+	[[text]]<div class="text">%s</div>[[/text]]
+  [[/list-item]]
+</div>
+TEMPLATE;
+		$expected = [
+			'result' => [
+				'clear' => [
+					'list-item' => '%s',
+					'logo'      => '<div class="logo">%s</div>',
+					'img'       => '<img src="%s" alt=""/>',
+					'caption'   => '<span class="caption">%s</span>',
+					'text'      => '<div class="text">%s</div>',
+				],
+
+				'content' => [
+					'%s[[logo]]<div class="logo">%s[[img]]<img src="%s" alt=""/>[[/img]][[caption]]<span class="caption">%s</span>[[/caption]]</div>[[/logo]][[text]]<div class="text">%s</div>[[/text]]',
+					'<div class="logo">%s[[img]]<img src="%s" alt=""/>[[/img]][[caption]]<span class="caption">%s</span>[[/caption]]</div>',
+					'<div class="text">%s</div>',
+					'<img src="%s" alt=""/>',
+					'<span class="caption">%s</span>',
+				],
+
+				'tag' => [
+					'list-item',
+					'logo',
+					'text',
+					'img',
+					'caption',
+				],
+			],
+		];
+
+		$result = $method->invoke( $templater, $tpl );
+		// This fails.
+		$this->assertEquals(
+			remove_spaces_recursively( $expected['result'] ),
+			remove_spaces_recursively( $result['result'] )
+		);
 	}
 }
diff --git a/tests/inc/functions.php b/tests/inc/functions.php
new file mode 100644
index 0000000..8f55c50
--- /dev/null
+++ b/tests/inc/functions.php
@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * Replace spaces.
+ */
+function remove_spaces( string $string ): string {
+	return preg_replace( '/\s+/', '', $string );
+}
+
+function remove_spaces_recursively( array $array ): array {
+	array_walk_recursive( $array, function( &$value ) {
+		$value = remove_spaces( $value );
+	} );
+
+	return $array;
+}