How do I make a GameObject carry across only 2 specific scenes?

Question

I have a GameObject in my main menu and help scenes that I want to carry across both scenes but be destroyed on all other scenes. I am having multiple issues with it such as it wont destroy on other scenes or when I go back to the previous scene it will generate 2 GameObjects and so on. Here is the script:

public class DestroyObject : MonoBehaviour
{
    void Awake()
    {
        DontDestroyOnLoad(gameObject);
        SceneManager.sceneLoaded += OnSceneLoaded;
    }

    void OnSceneLoaded(UnityEngine.SceneManagement.Scene scene, UnityEngine.SceneManagement.LoadSceneMode mode)
    {
        if ((scene.name == "Help") || (scene.name == "Main Menu"))
        {
            DontDestroyOnLoad(gameObject);
        }
        else
        {
            Destroy(gameObject);
        }
    }
}

Answer 1

You could have a gameobject in the scene called GAME_MANAGER. Add to it a script 'Game_Manager.cs'

have a public method inside of this script:

public static Game_Manager instance; //create a singleton instance to access these methods from other scripts.
private GameObject menuObject;  // store reference to the menuobject you want to activate

void Awake(){
// init the singleton instance if it is not already
if (instance == null)
     instance = this;
else
     Destroy(this);

DontDestroyOnLoad(gameObject); // make sure this object isn't destroyed after scene changes

menuObject = GameObject.Find("Name Of The Object"); // this is one way of many to 'find' the object you are wanting.
}

public void ActivateMenuObject(bool makeActive){
     menuObject.SetActive(makeActive);
}

You could call this 'ActivateMenuObject' from any script by accessing the singleton instance:

Game_Manager.instance.ActiveMenuObject(true);

or you could find another way , for example do it within the Game_Manager itself, or you could add another parameter to the ActiveMenuObject method asking for a GameObject, and then the method would SetActive the specified GameObject to the specified bool without needing to make a reference to the gameobject in the Game_Manager.

    public void SetObjectActiveState(GameObject obj, bool active){
     obj.SetActive(active);
}

I do hope that helps. I'm not an expert but I have been tinkering with Unity at noob level for a few years :) Good luck!