Actually, this would be a great time to use arrays!
You can add each of the actors to an array in the Level Blueprint (Say, ActorSet1 and ActorSet2). You can create these Arrays in the Level BP itself (Use “Actor: Object” Array) and then with the LBP open, you can drag those actors into the graph to add them into the Array.
Alternatively, if you don’t have a huge overhead, you can use tags to differentiate group 1 from group 2 and on BeginPlay, “GetAllActorsWithTag:ActorSet1”-> ADD UNIQUE to Array “ActorSet1” and do the same for Set 2, THEN do the other stuff using the arrays and a “ForEach” node to apply. 