Hey Robin
It sounds like you want to send a message to the actor that is overlapping the trigger volume? To the actual instance of the blueprint, once a certain component of that actor overlaps the trigger volume?
If that’s the case then you could make a BP that has a trigger as one of its components. Make an oncomponentbeginoverlap event node, and pull a wire off the “OtherComp” reference. Plug that into a getclass node, that goes into a class is child of node, if that is the class (of component) you want, then you cast the actor to the class (of actor) that you are looking for, and call a function in that class. Something like this;
Obviously I havent continued after the cast because I don’t know what you want to do, but if its a public function, you’ll be able to call it from the cast. So you could make a function in that actor class that accepts inputs if you want to send data to that class etc.
I hope I understood you correctly, let me know if thats what you were after!