How can I make players join servers based on their level?

Hello, So I'm pretty sure nobody will answer this but how can I make players join servers with similar levels.

It would be nice since tryhards wouldn't be able to attack new players. Also, if possible so that players could also join their friends.

I know how to do all of this but idk how to find the player's level on a different server and send them to the best one.

It would be nice if someone could help. Anyways Thanks!