I’ve been working on one scene of a game, that corresponds basically to one playable level. I’d like to make another level, that has much in common with the first, but not everything. The easiest way to do this, conceptually speaking, would be to duplicate the scene, then change the things in the copied scene that I want to be different. However, there is no obvious way to do this. Is there a non-obvious way?
It’s pretty obvious actually…Edit → Duplicate (or whatever the keyboard equivalent is on your OS), the same way you duplicate everything else.
You can also press Ctrl+D on 33Windows, if your scene is called "Level 1" the duplicated level will be named "Level 2" automatically.
I would like to recommend you select the scene that you want to copy and right click select ‘save as’. Give the copied new scene a new name and save it in the same asset folder of your previous scene. You will be able to edit the new scene without changing any of the previous one. You can also switch back to edit the previous scene as well. Don’t know whether this solves your problem. Hope it helps.
I explain here how to do it:
Different than the answers mentioned here, I speak of another way to duplicate a scene
- Open the scene
- In
Hierarchywindow right click on top of the scene and click"Save Scene As"and save with the name you want. That is going to open that scene right away in Unity.
I found a wayy!!! 
Not the most efficient but it is working though:)
So just duplicate the scene(Edit → Duplicate) and then i had to create another folder for my level 2 material. Then i had to change the material of every object that i wanted to change it’s location, color etc…