How to make enemies avoid other enemies' attack hitboxes

First, your box should be “overlap” not “block” if what you’re trying to do is to drive the behavior of the actor, e g, give the actor the knowledge to back up or side step, rather than just “push” on other actors.

Second, in the “on component overlap” event callback, you are given a reference to the actor that overlaps the box. Simply check whether the actor is yourself in there.