Before you get the expected responses I can say have you thought of the different obvious ways you could jump between different terrains? If sandbox in size and not too large you could have them all present at different locations and teleport between them in the simplest sense.
Otherwize i cannot tell if you want to just swap texture,s as if that’s the case you can definitely build that with UE4 within the current tutorials on youtube & blueprint knowledge as far as I’m aware.
The last obvious option is to spawn your level objects entirely by swapping out everything though how this is achieved is up to you but again is not difficult in general given the general knowledge you’d gain by learning the engine if you have not already by tutorials etc…
With all that said the forum here is excellent if you have a point question about a method of doing something, while showing you are familiar with the basics of the engine and are stuck on a particular part. In other words the community is not going to write your game for you, but I am going on a limb and state that you already know that
P.S. what is your exact question? I didn’t find it in your post.