hello, 

I have 2 questions,

When i remove admin from group default, he return after he join server again, how i can make admin never inside group default?

and

Inside betterchat is this correct?

priority for admin = 0

priority for mod = 1

priority for player = 2

Thankyou very much

All players are always under the default group, that doesn't have anything to do with this plugin. If you want only one tag to show, you'd need to set the config to hide all except for the highest priority group.

As Wulf mentioned, you can not leave the default group. Instead set the HideIfNotPrimary setting to true for the default group. That way the title will only be shown if the player is in no other group of higher priority.

Yes, the priorities you mentioned are set correctly.