I haven’t ran the run EQS from a blueprint yet, actually trying to find more info out myself about it now; however, I do know that the “querier” is the actor performing the EQS query, same as when you run it in a behavior tree. In the behavior tree, querier defaults to the controller running the behavior tree. You should be able to just plug a “self” pin into the querier pin and it would work, assuming you are running the node from within the blueprint you want to query from. I say should because I’m not sure if it must be a controller but I think it can be an actor.
Good luck, let me know if this helps!