Hello,
So, you can use the GET DISTANCE TO node and place it in a looping function that will instruct Unreal to keep track of all enemy’s proximities.
Keep in mind that if all the enemies are of the same class, then you will have to break the arrays with FOR LOOP functions or manually break them yourself.
Then you can create a behavior function/tree for the enemies that evaluate whether to attack or wait, depending on if their distance/hit react Boolean returns as TRUE or FALSE.