Regulate visibility objects by level/layer?

First I am a beginner in UE.

I have a terrain. For building this terrain I used BSP objects (poles) for creating terrain, ditches, dunes with specific dimensions. Actually I used the objects for reference.
Is it possible to move them to a separate level/layer, and next save this level/layer. So the objects are not in my main level anymore. When I need the objects in the editor again, I would like to import the level/layer again.

Greetings from the Netherlands

I am answering my own question, because it turned out to be a stupid question :-).
Link to use of layers link text

In world outliner, I made a new submap, moved all objects I want to hide to the submap.
Made a new layer, added the objects to this layer and turned visibility off for this layer.