I have 2 idea.
One is using Dual Axis.
Maybe this graph is a little bit difference from what you want.
But it needs not to change a view of data.
Please see [Waterfall] sheet of attached workbook.
Another one is using Union.
Maybe this graph is exactly what you want.
It uses self union query. One query is group by High Level Activity and another is total.
Please see [Union] sheet of attached workbook.
Please reply if you want further explanation.
20151202.twbx 24.7 KB