I have a feeling some of you may know exactly what I'm going to ask. There was an option that allowed the user to watch any existing mesh/pin animations to play in live-time, while tweaking and working on any one layers. Now I used to do this many months ago during when I first began to learn AE. For the heck of it I seemed to have forgotten how! If I knew what it was called, I probably would've found the solution sooner.

A visual example would be something that goes:
Select layer with object, place puppet pins, Ctrl + Click and move pins to record animation flow. Select second layer with another object, place pins, ctrl + click and move as needed; the previous used pins will, in live time, play in the window, while tweaking with the new layer of object.

Thank you guys so much!