I have a need to use one layer's contents as a selection for another layers contents. example: select layer 1 which is a circle - use that circle selection marque to select smaller objects on layer 2 that only fall within the circle selection. Of course, we've been doing this for eons in photoshop. I have the whole astute graphics suite but have not found a tool that does this yet. Any ideas?
I do not believe you can. Illustrator doesn't work on "marquee selections". Like all vector applications, Illustrator is object oriented. "Marquee selections" are more pixel-based.
You can manually use the Lasso Tool to select objects within a given area, but I think that's as close as you'll get.