BuddyPress.org

Yeah, it’s not all that easy to populate an xprofile dropdown dynamically. I can think of a few ways to do it, but it might be complex.

Here’s the general direction I’d move: http://pastebin.com/DM8YNzsq Obviously your $_POST array key will be something else, and you may want to do some data checking before saving. But that’s the skeleton of what you need.