1 click - just the entity you select
2 clicks - geometry immediately touching the primary object you select
3 clicks - all 'loose' geometry that touches the primary object you select
It's slightly different if the object under you mouse is a component:
1 click - selects the component
2 clicks - "opens" the component
3 clicks - "opens" the component, and..
- if your mouse is over a sub-component, selects that sub-component
- otherwise, selects all teh 'loose' geometry touchign teh face your mouse is over.
