Realm First! Battle for Azeroth Keystone Master

I've been asked many times back when I did the Legion one.

So unless it changed for BFA, this is how it worked :

In a 5 man setup, you need atleast 3 people from your server to trigger the R1, this is including connected realms so don't worry about it.

Example in my case (EU) :
Me-Kael'Thas > R1
Mate1-Kael'Thas > R1
Mate2-Arak'Aram (but connected to Kael'Thas) > R1
Mate3-ArgentDawn > nope (it was already done anyway)
Mate4-Archimonde > nope (but R1 was still available and done later on this realm)

On a side note, unless it changed, I remember back from TLK that player that changed realms X* days prior to the down are not eligible to the realm first.

* : I can' t recall but it's something like 7 to 30 days

Now in a "3 people from the same connected realms" situation, I don't know if the "other 2 who's been on the realm for X+ days", will get credit for the realm first.

You have to be on the server for 60 days after transferring to receive realm first.