How do I Make A Super Smash Bros. Like Character View Thing?

So, I'm making a sort of knock off of Smash Bros. and I want to implement the feature that when your enemy is off-screen, you see where they are and in the direction that they are.

If you've ever played Smash Bros., it's when your friend is very high up in the air and you can see their position with a little red bubble until they're back down.

Any help?

Thanks