From customer:

I have a dashboard from 3 different worksheets, each having a separate query.

Is there a way of combining all three datasets into bar chart clustered

For each date I want one bar of the green dataset, one from the blue, one from the purple

One possible approach is allow the user to create a new datasource by joining multiple datasources:

1. Add "Data > Join Datasource..." option
2. In the Join Datasource dialog:
   • New Datasource Name -- specifies the name of the combined datasource
   • Add Datasource -- click to add additional datasource to join
   • Edit Columns button for each added datasource -- click to select the columns to include
   • Edit Join button for for each added datasource -- click to specify the join columns and type of join (left, inner, right, outer)
   • Remove button for for each added datasource -- click to remove datasource from the combined datasource
   • Cancel
   • Save