This is the Unity package I use to manage scenes in my own projects. I work on a lot of small games so I always try to create this type of reusable, scalable and ready-to-use systems that allow me to just drop it into any project and have it ready in no time. The package includes:
Download and check the code from the GitHub Page: https://github.com/S-LucasSerrano/UnitySceneExtensions
Scene List Window
A scriptable object that holds a reference to a specific scene and has functions that allow to load it.
Scriptable object that allows to load scenes using a loading screen.
Component that modifies the fill amount of a UI image to show the progress of a loading screen.
Component that animates an effect meant to decorate the change between scenes.