Creating a custom editor viewport


I am currently trying to create an own editor viewport for my plug-in and I have hit somewhat of a dead end. So I have my viewport widget, client and scene. The problem is now that my editor viewport displays the same level as the engine editor viewport. So If I change something in the engine viewport the changes also happens simultaneously in my viewport. My question now is how can I change the scene that is displayed in my viewport?

I tried looking into the StaticMeshEditor and MaterialEditor, but sadly I wasn’t able to find anything. Thanks in advance :).