Group choosing actors and searching for files within a folder

In my project im trying to implement some saving and loading system for groups of actors(for example, a house full of props).
I was thinking about marking them in some way but cant figure out the best way to do it(maybe with some kind of area markers? Seems uncomfortable but thats what I tought about).
Also, I would like to save them in some inputed name(using the save game object) and later importing them back but without knowing the previously saved “groups”, using some kind of searching for all files within a folder. Any way doing this?
Maybe theres already something in the engine I missed and Im just overcomplecating it now.
Any advice is welcome : )
Btw, im using blueprints(I know how to code but never touched the ue4 c++ coding)
And sorry for any typos, not a native speaker.