How cast a event in another blueprint in mulplayer?

Hello , I have a problem, I know how works the multcast or run on server functions.

I need to start a player event in the blueprint of the weapon, it is very simple, in weaponBP> cast player BP > get player index and call the event, works perfectly .

but how is a multplayer game the index player let the event run on just one play

like the image: we see index on run that event in one player. player 0 in case;
or get all actor, run on all player at same time. this is a firing event like a shooter game.

what i do for cast the event that works like a multplayer shooter ?