Parent, child objects... what about grandparents?

I may have missed something somewhere... or this question could have been asked a thousand times before...

But can objects have any form of hierarchy? So for example, a car object has four wheel objects which are it's children.... the wheels each have a child hubcap object.

This makes the car the grandparent of the hubcaps.

Currently it seems that I can only make one object the parent of the entire group... there can be no subgroups.

Is this correct? Or have I missed something

Thanks,

AFAIK, there are no subgroups.

The root prim of the object defines the object's coordinate system, and everything else is a child and moves relative to it.

A hierarchy would be wonderful.. but it doesn't exist

we do for sit targets, it works that way last linked is first seat
and second to last linked is second seat ect...
and there is link numbers but its linear no branches
but i guees you could make your own hierarchy using link numbers
-LW