Is there any way to load a level in the editor using blueprints, python or c++ (world composition)?

So when using world composition I would like to be able to programatically select some tiles and load them. Much like selecting some tiles in the world composition window and loading them.
Is this possable ? So far I have found something to load a level, which says it basically totally changes maps and loads a different persistent level, and I have found something to load a level instance (Not sure what I want one of them for !) .But I have found nothing just to load a level i.e. a tile in world composition (A level streaming proxy ?) !

Oh and at run time I think I can use “get streaming level”, but in the editor IsValid always returns false on the level it returns.