how to make an object from Global object back to scene object?
Can you tell me what is a global object first? I am not understanding that perfectly.
For scene object, I guess you think about an object on scene. I understand that. But a global object outside of a scene? Is that an external layout object?
In GDevelop every object is local by default, which means it is available only in the scene where you created the object.
But you have the option to set an object to be global and this way make it available in every single scene in your game. So in case you want an object to be available in every single scene, you can just simply set the object to be global and you don’t need to add the object manually to each scene and in case you make changes to the object in one scene, it changes in all scenes and you don’t need to go through each scene to make the same changes to the same object.
I don’t think you can but maybe I’m wrong 
You are right, global object doesn’t mean the instance is shared between scenes, the instance values are not saved. A global object lets you create an instance from the same global base object.
If you have an object that is used in multiple scenes, and you set that object as global, you can edit it once and the changes will be available in all the scenes without having to copy/paste, it save space in the project too.
To solve your problem, before leaving the scene, you’ll have to save the instance properties you want to retrieve in global variables. Then you create another instance in a new scene, and set the properties from the saved global variables 