Sort of, but not exactly. Here's what I'm trying to do; I'm using the super-store book to demonstrate.
In this highlight table, I have the category and region in a cross-tab set up, with sales in my cells. Category is a hierarchy, with sub-category under it. So, with category selected, here's what I get:
Now, if I click on the drill-down plus sign next to cateogry, I get this:
See how the sub-category is ONLY showing the sub-categories that nest under a particular category? I didn't have to do anything to make this work; it's just a natural reaction to setting up this table. No formulas needed. My problem in my actual workbook is that using this exact set up, what I get is ALL sub-categories showing up under each category, but with so many of them blank (because they have no values), I get a lot of dead space. It would be like this example above, but with all the technology items showing up in the row for furniture, but with no data. Make sense? I can't figure out why it works here in this example, but with an identical set up in my other workbook it doesn't.
How did you set up your data? Used any joins? Can you at least show us your database schema? It's hard to pinpoint your problem without looking at your data.