how access a global function from all blueprints

Hello,

How can I create a global function that can be called from all other blueprints in the level?
More specifically I want to be able to change the blend amount of a post process volume, when I enter a menu, and when I exit an UMG menu.

So if I create a function that changes the blend amount I can call it in my UMG graph, when i exit the menu, also I will be able to call it from the FirstPersonCharacter blueprint.

Any help would be much appreciated.

You’ll probably want to look into Direct Blueprint Communications:

thank you.