Basically, there are two things. One thing is to spawn the new actor, and this part is easy. You can see an example in BP_PhGrabChar in the screenshot below. The other part is to manage the inventory of assets you can spawn, which includes the UMG menu, the icons, the “database” part and other stuff like that. And this is something different from snapping tool, it’s really like an inventory system, it really depends on the rest of the game.
I wanted to keep those examples very generic, so I didn’t do anything like that.