Michael,
Okay, I see what your saying. Move each group independently from each other by animating the group or image in the group with key frames or a Basic Motion Behavior. Use the Camera to animate all of your groups.
I like to think of it like you would if you where shooting it with your “real” camera. Think of the Objects as props/talent you can tell to move (aka Keyframes / Behavior). To create movement in the whole scene you would move your camera. Hope this helps.
Stephen Smith
Lone Peak Producitons
Check out my DVD Money Making Graphics & Effects for Final Cut Studio 2