[Bar chart] multiple group by categories

[graceguo-supercat]

Is your feature request related to a problem? Please describe.
User can create bar chart with multiple group by categories. For example, i want to group by severity (4 values: critical, high, medium and low) and ticket_status(2 values: ticketed and non-ticketed)

The result bar chart has 4 x 2 bar for each month.

Describe the solution you'd like
Now we want to stack the Ticketed and Non-Ticketed bars for each severity. so it shows Critical ticketed vs non-tickets, High ticketed vs non-ticketed, Medium ticketed vs non-ticketed, and Low ticketed vs non-ticketed.

Is it possible for bar chart to allow user choose Primary and Secondary groupby categories (or by the order that user added into GROUP BY control)? So that we can display secondary category inside primary category bar 🦸 📊

[junlincc]

Thanks for the requests! @graceguo-supercat we are planning for new Echarts Bar, feel free to o file all requirements in this threat, we will try to get all in.