Okay, I tried to implement what you wrote and made in the screenshot, buuuut didn’t work at first. So maybe some more information how I initially set it up. I must mention I am trying to learn programming at the moment, so I am not yet familiar with many things, so an explanation for dummies here and there is much appreciated! Knowing what is supposed to happen in your example is (for me at least) a big help to learn and understand these things.
I have the character BP for the turret. There is a sphere collision that constantly checks, if an enemy is within the sphere. If so, I can press a button (for testing purposes) to put all detected enemies in an array (not yet based on distance, I am just using six dummies for now) and then spawn a projectile BP six times (so six instances) and call an event in the projectile BP, so they would set their homing target when they spawn.
Maybe that is the wrong approach, I don’t know. It has always and only worked for one enemy so far.
Now I am not sure where I would put what you made in that screenshot and if I need to change something in my setup.
But I am still glad for your help so far! That goes for everyone here of course.