Showing Multiple Values in TreeMap

I'm basically wondering how I can get summarized values, such as percentages and totals, summarized from different columns, to show up next to or on top of each other in the same box like so: 

I'm pretty sure I would need some script for it, as the default catgeory and data label features of the Treemap don't allow me to do this, so I was wondering if it's possible to edit something about the logic of a treemap or perhaps make custom features for a Treemap in general?

I have never scripted in PowerBi so any help would be much appreciated!

Thanks in advance,

Bas