If you really want an official level, (I don't know about where you live, but) in Canada there are rider level tests, and pony club levels. They can give you an idea of where you fall...
The role you play at your barn (if there's a big enough group of riders) can also give you an idea of where you are, for example I know I'm more intermediate/advanced because I'm one of the people who works with training babies, and has the job of schooling any of the school horses who are being "bad".
I wasn't really concerned until a trainer I knew asked my to be a catch rider for their show team. That was my realization that I was advanced/intermediate
It basically comes down to how much feel and timing you have as a rider, which translates into what all you can get your horse to do. There's really no set rulebook outlining what each level can and can't do, as it depends on both the rider and the horse's capabilities.