How to get the overrides child of GameObject in script

Hello.
Im currently working on a tool that when I'm saving a Prefab Instance in scene as PrefabAsset into the asset folder, it will look into that prefab instance and check the child if they had any changes and then automatically saving them into prefab assets.
The problem is I want to get the list of this overrides child like this image. In this image i want to get cell_0 GameObject, which is the override child.

How I do that from script. Thank you

 

I don't understand your question exactly, and I can't see from the image what's special about Cell_0 specifically. But you'll find the APIs to get objects with various types of overrides in the PrefabUtility class:
https://docs.unity3d.com/ScriptReference/PrefabUtility.GetAddedGameObjects.html
https://docs.unity3d.com/ScriptReference/PrefabUtility.GetAddedComponents.html
https://docs.unity3d.com/ScriptReference/PrefabUtility.GetRemovedComponents.html
https://docs.unity3d.com/ScriptReference/PrefabUtility.GetObjectOverrides.html

 

you find a child object, then used this method.

public void GetChildObject(Transform parent, string _tag)
{
for (int i = 0; i < parent.childCount; i++)
{
Transform child = parent.GetChild(i);
if (child.tag == _tag)
{
yourlist.Add(child.gameObject);
}
if (child.childCount > 0)
{
GetChildObject(child, _tag);
}
}
}