Is it possible to subscribe to CustomEvent of another Class Blueprint (not parent)?

I know i can subscribe to CustomEvent of (Parent Class Blueprint) from (Child Class Blueprint).
But how to subscribe from totally another Class Blueprint?

I become realize, that Events in blueprints do not behave like events/delegates, they behave like Virtual Functions. So i will assume, that they cannot be “subscribed” outside of owner, they can only be “overriden”.