Use “middle man” setup for all that.
In your case middle man should be one of those:
- game mode (easiest to get, simple in non multiplayer games)
- BP_HUD, create hud , it is logical widgets report to hud
- player controller, or they report to it
- player pawn. player character, same as above
When you pick your middle man, create there CUSTOM event, like “Widget did something”
Then in widget get reference to middle man (easiest is to get game mode), cast to BP_GameMode , then trigger event there, pass over variables from widget.
In case of game mode, make sure its set in project settings to your game mode, and all stuff in it is set to whatever you want to use as defaults in your game.