Hi @simonkelly
For example,
Lets say you make an actor with 4 triggetboxes ,and set up all the OnActor begin overlap(Triggetbox1,2,3,4).
Pin out the OtherActor, and if you are using pawns, you will need to use a node to get the player controller of the pawn
Now set a variable to store this info like an array of int.
So the index are the players and the stored number are the triggerbox they are in.
If player 1 entered the trigger 4, set array elem index 1 to 4.
When they leave the trigger , set the relative array index to 0.
Now whenever you want you can start a custom evento to make a loop check. for the array and define the correct output for every combination you need.
Making this an actor you can also spawn it only on the server,
or use "Has Authority node "to make it work only on the server.