High Split Butterfly
I've always found split butterfly moves quite hard to learn as I'm a lot more natural with weave moves. This one however is a good starting point, I'd recommend learning the windmill before this as it used pretty much the same co-ordination and is easier to click with. Once you have that do a normal butterfly in front of you and drop one arm behind your head on the upswing, bring it back to the front on the next upswing and carry on with the normal butterfly, try this with the other arm and when you're comfortable with that you're ready to start a high split butterfly