If I've understood correctly, you're looking to group your levels of hierarchy - Perhaps this post will help you and your use case? The specified item was not found. - Let me know how it goes!
I have the same issue and I was worried it's me being stupid.. Which I may well be.
My example is....
I have a 2 panes on a Dashboard showing the same data in 2 ways;
1. A table with a 3 level hierarchy and the sum of a product. Top level hierarchy is visible until drilled through.
2. A pie chart showing the sum of a product by the top level hierarchy. So is showing % product per level 1 hierarchy.
The problem is, if I want to filter on a single top level item in 1.table and drill down a level the 2.pie filters but does not drill so ends up as a big 100% blob. I'd like the pie to recognise it's using the same hierarchy as the table and drill down as I drill down. Because I also want the moon, I'd also like it re-shade the pie to the level.... Eg in the 2.pie, item one on level one is red... After I drill the 1.table and the 2.pie drills, instead of a big red blob of now level 2 data it's shaded the Level 2 segments... So it's colour drilled!
Thanks for any help you can give