I would like to view one comp that has the another comp as part of its layers at the same time as adusting and seeing the display of this other comp? Is this possible? If so how? Thanks for any advice.
Mylenium is right. For information about locking viewers and using an edit-this-look-at-that (ETLAT) workspace setup, see the
"Work with viewers" section of After Effects CS3 Help on the Web.
This way of working is made much easier in After Effects CS4. In After Effects CS4, certain keyboard shortcuts and other commands target the composition that you're viewing rather than the one that you're modifying.
"Viewers" section of After Effects CS4 Help on the Web.