I've got a specific case/scenario, where I'm not sure how to play it.

There's this girl that I've got a thing for that basically isn't really an acquaintance, but not really a friend either.

Towards the end of college, my group of guy friends became friends with this group of girls (of which the girl I'm talking about was in). However, I only really became friends with a number of them but not that close to the girl of which this thread is about. In addition, she left the country right after graduation for a couple of years worth of work and just recently came back. Now, I see her at almost every function we go to since we all share the same mutual group of friends.

This should be ideal for me since I haven't developed the relationship and put myself into the friend zone. However, where it is complicated is that I've had been hooking up on and off with one of her best friends in her group. It hasn't happened in a while, and I'm over with that girl but I don't know what would be the best course of action here...if any. In addition, since she's been at almost every club, party, bar, function, event, etc... she has seen me pursue, leave and hook up with a other girls.

all the other girls in her group, including the one I had been hooking up with, are really good friends of mine and I wouldn't want to burn those bridges. Don't know if it's even possible to pursue this girl without doing so. In addition, she has a certain perception of me from all the functions we've been at together, despite us not having directly interacted all that much. Thoughts?