Add Custom property : ComponentRoot?

I am trying to make a third person dungeon map from a fresh start copying the entire hierarchy (each folder and script ) from a new core-base map to an empty map.

In advance I have to say that I do this in order to learn lua, scripting, dependencies, etc....

I have alredy do all the tedious job except the "AddCustom property: ComponentRoot" ....
I have been trying to drag all folders, containers, texts, ...etc to the "button" but never achieve the "ComponentRoot Core Object Reference"

detalleCodigoCore