How does post-SA recruiting work?

Curious on how the process is for someone who does a SA at BB in NYC, and then wants to shop his offer around and look at other firms. I saw some previous posts on how it works in London, but was looking for feedback specifically for NYC. How does it work if you summer, get an offer, and then want to interview elsewhere? What is the timeframe, how do you get in contact with other firms, similarity to regular full time, etc? Thanks