Can i divide an already created map in world composition?

Hi I have started a large map landscape in ue4 with a lot of work put into it. I am wondering if I can add that map in world composition and just divide it into sections to break it up instead of just adding adjacent maps around it? I added the level map , but in the minimap I can only see a little white icon . I cannot see any of my terrain or anything. thanx for any help