Apple Motion 3 - Manual (Page 319)

Chapter 3 Basic Compositing 319
To expose all drop zones in a project:
1 Use the Library or File Browser to locate an object you wish to import into the project.
2 While holding down the Command key, drag the object onto the Canvas.
The object you are dragging to the Canvas is displayed as a thumbnail, and a curved
arrow replaces the pointer until you drop the object. Active objects explode and
rescale in the Canvas so that you can see them all at once. Moving the pointer over an
object reveals its Layers list name.
3 Drop the object onto its target.
The object replaces its target, everything moves and rescales back to their original
positions, and the playhead moves to the first frame of the dropped object.
Exposing the drop zones