This Unreal 5.3 Gameplay Ability System video is about building a player progression system based on Levels and Experience Points.
We start by thinking about whether Class/Blueprint Variables or GAS Attributes should be used, and then update the SomeMap Map to fence in the enemies for testing. Next we create the Progression Widget Blueprint, then add Gain XP, Gain Level and Calc XP Needed Functions to the Character, and ensure the Widget is being updated. Lastly, purely to show off some basic Unreal debugging, a function is left out until we trace through a bit and add it, showing off the fancy XP Progression.
https://dev.epicgames.com/community/learning/tutorials/GplZ/unreal-engine-32-player-progression-experience-points-let-s-make-a-top-down-shooter