Hello!
Is it possible to merge two or more levels into one?
It would be far easier and faster to work on a single part of the map at a time, as rendering times would be minimized. It would be of no use however if I can’t merge it with other parts of my map.
If it’s possible to do this, how can I do it?
Just copy everything from your other map + open the new one + paste it. Or just use the world browser. There you can just add your maps to your other level (level streaming) 
Okay, copying worked fine so far with a small level. I have no idea where a “world browser” is, though. Can you list the steps on how to find and use it?
Also, when I copy one level into another, I’m unable to edit the copied content, which makes it impossible to make the transition between the two seamless. Is there a way to properly merge them and make both editable?
I’ll quickly correct me there:
It’s possible to edit both levels when I select them individually. However, I can’t use a sculpt tool to edit them at the same time for a seamless transition.
Side effect: If I try to enter the play mode, my character falls through the ground.
No it’s not possible when you use two different landscapes -> you can just edit one at the time
With “ground” you mean the landscape? -> click on the “build” button and try it again
I see that it’s done differently than what I imagined.
I started a completely new project without the 700MB starter content and a smaller level map. When I’m expanding it it’s possible to select certain parts of it and add to a differet level through the level viewer, right? So not everything has to be loaded at the same time?
I think you can just copy everything into the different level (+ you can use the “move level” feature which you can find in the manage tab) -> after you have moved it to the new level, you can stream it
“Just copy everything from your other map + open the new one + paste it. Or just use the world browser. There you can just add your maps to your other level (level streaming) :)”
What do i copy ? i have two maps or levels how can i combine them? Does this still work in 2020 i can not combine these 2 maps i have!
Wanna bump this. It is made to sound easy but i think a noob like myself may need a little more step by step breakdown. @ClockworkOcean maybe you can be super hero here again? I think that level streaming may be the thing to rid me of all my problems with saving and player starts. I think if i can take all of my maps, copy them over in this “world browser,” and just use character transform to move the character instead of loading each map, im certain i can finally break free of my current struggles. You have any insight here? Hopefully im not just pestering you at this point 
You have to differentiate between ‘world partition’, and ‘level streaming’.
WP is the new Epic offering. You would just lay everything out in one go, and the grid system would do all the loading and unloading for you.
LS is for when you want finer control. It’s the same sort of concept, and no doubt uses core code with WP, but you have to specifically say which bits loads when, using either blueprint, or volumes.
I would say, maybe, WP is a possible route for you. As the player positioning, spawning and control is much worse with streaming that with ‘open level’.
Right on!! Just enabled world partition and this really fixes a lot of my problems. I merged all my maps and got rid of all player starts, now i can use teleport and all destroyed assets are still gone when i come back. This is GRRRRRRREAT!!!