Trigger some event from other blueprint on button press?

When i press a button using my main character, i want to trigger an event in some other blueprint… ? how can i do this…??

You’ll need to cast to it. You can use Get All Actors of Class and filter by the other BPs class, use Get to return its instance, and plug that into a Cast to [its class]. From there you can store the cast output as a variable that will give you control overall events, functions, and public variables of that BP instance. Simply place the variable, drag out the pin, and call your event. Only that initial cast is necessary, and I recommend doing it as early as possible, like on Begin Play if it’s already in the level.