diff --git a/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.test.tsx b/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.test.tsx
new file mode 100644
index 0000000000000..c1addc84dd656
--- /dev/null
+++ b/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.test.tsx
@@ -0,0 +1,102 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { mountWithIntl, nextTick } from 'test_utils/enzyme_helpers';
+import { actionTypeRegistryMock } from '../../../../../triggers_actions_ui/public/application/action_type_registry.mock';
+import { alertTypeRegistryMock } from '../../../../../triggers_actions_ui/public/application/alert_type_registry.mock';
+import { coreMock } from '../../../../../../../src/core/public/mocks';
+import { AlertsContextValue } from '../../../../../triggers_actions_ui/public/application/context/alerts_context';
+import { AlertContextMeta, MetricExpression } from '../types';
+import { MetricsExplorerMetric } from '../../../../common/http_api/metrics_explorer';
+import React from 'react';
+import { Expressions, defaultExpression } from './expression';
+import { act } from 'react-dom/test-utils';
+// eslint-disable-next-line @kbn/eslint/no-restricted-paths
+import { Comparator } from '../../../../server/lib/alerting/metric_threshold/types';
+import { MetricsExplorerResponse } from '../../../../common/http_api';
+import { validateMetricThreshold } from './validation';
+
+describe('Expression', () => {
+  async function setup(currentOptions: {
+    metrics?: MetricsExplorerMetric[];
+    filterQuery?: string;
+    groupBy?: string;
+  }) {
+    const alertParams = {
+      criteria: [defaultExpression],
+    };
+
+    const mocks = coreMock.createSetup();
+    const [
+      {
+        application: { capabilities },
+      },
+    ] = await mocks.getStartServices();
+
+    const context: AlertsContextValue<AlertContextMeta> = {
+      http: mocks.http,
+      toastNotifications: mocks.notifications.toasts,
+      actionTypeRegistry: actionTypeRegistryMock.create() as any,
+      alertTypeRegistry: alertTypeRegistryMock.create() as any,
+      docLinks: mocks.docLinks,
+      capabilities: {
+        ...capabilities,
+        actions: {
+          delete: true,
+          save: true,
+          show: true,
+        },
+      },
+      metadata: {
+        currentOptions,
+      },
+    };
+
+    const validationResult = validateMetricThreshold([alertParams.criteria]);
+
+    const wrapper = mountWithIntl(
+      <Expressions
+        alertsContext={context}
+        alertInterval="1m"
+        alertParams={alertParams}
+        errors={validationResult.errors}
+        setAlertParams={(key, value) => Reflect.set(alertParams, key, value)}
+        setAlertProperty={() => {}}
+      />
+    );
+
+    const update = async () =>
+      await act(async () => {
+        await nextTick();
+        wrapper.update();
+      });
+
+    await update();
+
+    return { wrapper, update, alertParams };
+  }
+
+  it('should prefill the alert using the context metadata', async () => {
+    const currentOptions = {
+      groupBy: 'host.hostname',
+      filterQuery: 'foo',
+      metrics: [{ aggregation: 'avg', field: 'system.load.1' }],
+    };
+    const { alertParams } = await setup(currentOptions);
+    expect(alertParams.groupBy).toBe('host.hostname');
+    expect(alertParams.filterQueryText).toBe('foo');
+    expect(alertParams.criteria).toEqual([
+      {
+        metric: 'system.load.1',
+        comparator: Comparator.GT,
+        threshold: [],
+        timeSize,
+        timeUnit,
+        aggType: 'avg',
+      },
+    ]);
+  });
+});
diff --git a/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.tsx b/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.tsx
index e7e917a8510a3..77f6285c323c3 100644
--- a/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.tsx
+++ b/x-pack/plugins/infra/public/alerting/metric_threshold/components/expression.tsx
@@ -4,7 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { debounce, pick } from 'lodash';
+import { debounce, pick, omit } from 'lodash';
 import * as rt from 'io-ts';
 import { HttpSetup } from 'src/core/public';
 import React, { ChangeEvent, useCallback, useMemo, useEffect, useState } from 'react';
@@ -71,6 +71,7 @@ const defaultExpression = {
   timeSize: 1,
   timeUnit: 'm',
 } as MetricExpression;
+export { defaultExpression };
 
 async function getAlertPreview({
   fetch,
@@ -481,7 +482,7 @@ export const Expressions: React.FC<Props> = (props) => {
                 id="selectPreviewLookbackInterval"
                 value={previewLookbackInterval}
                 onChange={onSelectPreviewLookbackInterval}
-                options={previewOptions}
+                options={previewDOMOptions}
               />
             </EuiFlexItem>
             <EuiFlexItem grow={false}>
@@ -642,6 +643,7 @@ const previewOptions = [
     }),
   },
 ];
+const previewDOMOptions = previewOptions.map((o) => omit(o, 'shortText'));
 
 const firedTimeLabel = i18n.translate('xpack.infra.metrics.alertFlyout.firedTime', {
   defaultMessage: 'time',
diff --git a/x-pack/plugins/infra/public/alerting/metric_threshold/components/validation.tsx b/x-pack/plugins/infra/public/alerting/metric_threshold/components/validation.tsx
index da342f0a45420..2221d3cd4fe12 100644
--- a/x-pack/plugins/infra/public/alerting/metric_threshold/components/validation.tsx
+++ b/x-pack/plugins/infra/public/alerting/metric_threshold/components/validation.tsx
@@ -50,7 +50,7 @@ export function validateMetricThreshold({
     if (!c.aggType) {
       errors[id].aggField.push(
         i18n.translate('xpack.infra.metrics.alertFlyout.error.aggregationRequired', {
-          defaultMessage: 'Aggreation is required.',
+          defaultMessage: 'Aggregation is required.',
         })
       );
     }
diff --git a/x-pack/plugins/triggers_actions_ui/public/common/expression_items/threshold.tsx b/x-pack/plugins/triggers_actions_ui/public/common/expression_items/threshold.tsx
index 09acf4fe1ef68..fe592aadb37a5 100644
--- a/x-pack/plugins/triggers_actions_ui/public/common/expression_items/threshold.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/common/expression_items/threshold.tsx
@@ -136,14 +136,14 @@ export const ThresholdExpression = ({
                 ) : null}
                 <EuiFlexItem grow={false}>
                   <EuiFormRow
-                    isInvalid={errors[`threshold${i}`].length > 0 || !threshold[i]}
+                    isInvalid={errors[`threshold${i}`]?.length > 0 || !threshold[i]}
                     error={errors[`threshold${i}`]}
                   >
                     <EuiFieldNumber
                       data-test-subj="alertThresholdInput"
                       min={0}
                       value={!threshold || threshold[i] === undefined ? '' : threshold[i]}
-                      isInvalid={errors[`threshold${i}`].length > 0 || !threshold[i]}
+                      isInvalid={errors[`threshold${i}`]?.length > 0 || !threshold[i]}
                       onChange={(e) => {
                         const { value } = e.target;
                         const thresholdVal = value !== '' ? parseFloat(value) : undefined;