This particular sentence I found someone speaking to a person worried about some problematic situations. I searched the web and got that nights = at night. And, up = A problem(could be).
So, Is she asking, "What were the other problems you faced at night?" OR the meaning is all different?
Note: The given question has been taken from 13 reasons why, ep. 4(at 18:18).
The scene goes like this:
Hannah : I just couldn't sleep last night.
Friend : Were you obsessed with history exam or something?
Hannah: Oh, no!
Friend : What else have you up nights?
Hannah : I think someone was taking my pictures.