You can’t access the level blueprint from other classes, and you probably don’t want to anyway because each one will be different and specific to that level. While you can sort of do this in C++, I really wouldn’t recommend it anyway. You can however get the name of the current level, if you need to.
Level Blueprints are only really designed for map-specific logic (such as a one-off door opening or starting a level sequence etc) - you shouldn’t be putting pause menus or general game logic in there (I mean, you can if you really want to - but it’s far from the best approach). To be honest, I don’t think I’ve ever actually needed one.
A good design is to store and reference all of your UI from a HUD class, so that it’s managed from one central place that’s easily accessible. That way you can tell the pause menu to be removed from anywhere, even the level blueprint.