Retain higher-level detail when drilling down in matrix

Hi, Greg_Deckler--

#1, I want to sincerely thank you for trying this hard to help me with my problem.

#2, I am not working in Excel.  I am trying to recreate functionality that exists in Excel in a Power BI Matrix.

#3, my client is not satisfied with the default behavior of the forked arrow. 

The issue is that while the single parent level appears with all of its children, the rest of the items at the parent's level disappear.  My clients would like all values at the parent level to remain, unexpanded, with the selected level drilled-down to its next level of detail.

That's my problem.  Do you know of a way in Power BI to give my client what they want?

I'm open to using something other than a matrix.

I'm open to using custom visuals.

I'm open to anything in the Power BI universe.

Thank you again, truly, for taking the time to understand my problem and to offering me help.  I've looked for assistance in a lot of places, and your efforts to help me are really making a difference and helping me to keep going.