Side by side stacked bar charts in a time series with two dimensions

[personofnorank]

Use case: a set of data with a time field that you want to display in a time series bar chart, and group by a primary and secondary dimension. For instance monthly sales grouped by product and region. Superset can do this for one dimension, say product - it shows a bar for each product in a given month either side by side or stacked depending on your preference. What I want is to make use of the side by side and stacking capabilities at the same time to show, for instance, a bar for each product in a given month stacked by region, or vice versa depending how I order the dimensions.

@sfirke tagging you as per Slack post, thank you.