How to put seperate scenes together into one game

So I have built a Unity Map with a Main Menu and then three levels. However each level has been built into separate folders (this includes the main menu). I was wondering how I put them together correctly into the same folder so I can build the game.

I attempted to do this by dragging and dropping each into the same folder, however each map clashed with one another and deleted/hid objects. I did rename the terrains so they wouldn’t clash, but they still do (terrains).

Any ideas? Thanks!

Each level or menu should be in another scene. You can create those from the menu → file → new scene.

To load levels, add all the scenes to the building settings: menu → file → build settings, and drag the scene files from the project folder into the window.

To load a level, use the Application.LoadLevelfunction. You can enter an integer as parameter to load a certain level. These integers are displayed in the building settings (its the numer right of the scene name)