Matrix Drill Down

I have a Matrix Visual with Category as Rows and Months as Column and Sales as Values
I'm asked to add Sub Category under Category in Matrix. (which is easy as drag and drop)
I also have Sub Category as a slicer.

Question:
I need to implement a solution when user selects a Sub Category or multiple Sub Categories then Matrix should expend, but when all Sub Categories are seelected the Matrix should collapes automatically, without using Drill Up and Down button.