Weapon Selection Menu

Hi everyone, I’m trying to create a FPS game but I have no idea on how to create a weapon selection menu. What I want to create is a menu which is situated in the menu level but has effect in the playable one. Something like Titanfall 2’s menu. I already have a weapon base system with 2 children weapons, but I don’t know how to use them in a widget and keep the selection saved (sorry for my english).