This Unreal 5.3 Gameplay Ability System video is about persisting Player Progression values across maps and game launches.
We start by creating the Char Data Save Game Blueprint with XP Variables. Next, we run through the Load Data Function and then the Save Data Function, and ensure both are being called, followed by some gameplay.
https://dev.epicgames.com/community/learning/tutorials/0JLy/unreal-engine-33-player-progression-saving-and-loading-let-s-make-a-top-down-shooter