Nested DataGroup objects

is there a good way to nest a DG within a DG?

For example, let's say I have a piece of mechanical equipment (DG-A) that has an electrical component (DG-B).  That electrical component is typical across different catalog types.  (DG-C,. DG-D, etc.)

I don't necessarily want to roll up different reports from DG-A, DG-C, DG-D...i just want to have a single report for DG-B across the rest.

I can do this manually...that is place the equipment, and then place the electrical component (which is not just data, but a physical piece with its own data), but I'm trying to see if it can be accomplished all at once.

I'd also like the electrical component to know the object it's connected to... (yes, hosted, I didn't want to use that term so folks don't tell me it can be done in another program...I know it can be done elsewhere, I'm trying to be generic here in the scope)

thoughts?