Setting health bar visible to only enemy clones?

I've created health bars for my enemies that are just clones of one sprite, and it's working fine, if I shoot an enemy, only that enemy has his HP bar decreased, but now I'm trying to set these enemies HP bar only visible when I shoot at them (and then they'll go invisible again and only show up if I shoot again), but differently from their HP decrease, if I shoot one enemy, all the bars turn visible. I tried some things but nothing worked so far.

Probably the hp bar doesn't relate to the enemy in any way. Check out 'Containers' where you can create an enemy and an hp bar together and it will always pick its associated instance. Other conditions may also work such as pick hp bar overlapping enemy or hp bar nearest to enemy.