Hiearchical dataGrid with composite keys

I try to construct a grid to show a parent-child relationship with 3 levels in hiearchy. My primary keys are composite keys (using more than one column)

Here is my situtation:

(1) I was able to construct a grid with 3 levels in hierarchy, however, I was able to do this ONLY IF my primary key is NOT composite (primary key which uses a single column
(2) If I use a composite key, the grid only shows 2 level dow

Is this possible to do in .NET (3 levels in hiearchy and each table uses composite keys)?
Do you have a sample (or instruction) on how to build this? I have searched for it almost entire Internet!

Thanks muc
-Than