Beginner: Can read the basic syntax, knows about E.G. Monads and folds
Intermediate: Understands and can use the more advanced classes like Applicative, Arrow, lenses, and how to use things like fix
Advanced: ??? Makes new powerful classes/libraries like Pipe, Conduit, or Netwire? Can easily translate a problem domain into a concise and elegant type representation.
Maybe there needs to be some more layers in there, I don't know... also the advanced level feels weak to me. I'm still somewhere between beginner and intermediate myself.