Cfrgtkky

In the first script:

using System.Collections;

using System.Collections.Generic;

using UnityEngine;



public class GenerateStairsUnits : MonoBehaviour

{

    [Header("Stairs Units Prefab")]

    public GameObject stairsUnitsPrefab;

    [Space(5)]

    [Header("Settings")]

    [Range(1, 20)]

    public int numberOfUnits = 1;

    public static GameObject Unit;



    private int oldNumberOfUnits = 0;



    // Use this for initialization

    void Start ()

    {

        oldNumberOfUnits = numberOfUnits;



        var unitsParent = GameObject.Find("Stairs Units");

        for (int i = 0; i < numberOfUnits; i++)

        {

            Unit = Instantiate(stairsUnitsPrefab, unitsParent.transform);

            Unit.name = "Stairs " + i.ToString();

        }

    }



    // Update is called once per frame

    void Update ()

    {



    }

}

So now under Stairs Units I have for example 5 Stairs (Stairs 0 , Stairs 1, Stairs 2, Stairs 3, Stairs 4) that are a copy of this script:

using System.Collections;

using System.Collections.Generic;

using System.Threading;

using UnityEngine;



public class GenerateStairs : MonoBehaviour

{

    [Header("Stairs Prefb")]

    public GameObject stairsPrefab;

    [Space(5)]

    [Header("Platforms")]

    public bool addPlatforms = false;

    public GameObject platformsPrefab;

    [Space(5)]

    [Header("Settings")]

    public float delay = 3;

    public int stairsNumber = 5;

    public Vector3 stairsStartPosition;

    public Vector3 stairSize;

    public Vector3 stairsSize;

    public float stepWidthFactor = 1f;



    private Vector3 stairsPosition;

    private GameObject stairsParent;



    // Use this for initialization

    void Start()

    {

        stairsParent = new GameObject();

        stairsParent.name = "Stairs";

        stairsParent.transform.parent = GenerateStairsUnits.Unit.transform;

        StartCoroutine(BuildStairs());

    }



    // Update is called once per frame

    void Update()

    {



    }



    private IEnumerator BuildStairs()

    {

        for (int i = 1; i <= stairsNumber; i++)

        {



            stairsPosition = new Vector3(

                    stairsStartPosition.x,

                    stairsStartPosition.y + (i * stairsSize.y),

                    stairsStartPosition.z + (i * stairsSize.y) * stepWidthFactor);



            GameObject stair = Instantiate(

                    stairsPrefab,

                    stairsPosition,

                    Quaternion.identity);



            stair.tag = "Stair";

            stair.transform.parent = stairsParent.transform;

            stair.transform.localScale = stairSize;



            yield return new WaitForSeconds(delay);

        }



        stairsParent.AddComponent<MoveObjects>().Init();

    }

}

Now on the second script the "Stairs" I want to be a child of each stairs unit:
For example under Stairs 0 should be Stairs. Then under Stairs 1 there should be also Stairs and also under Stairs 2 and Stairs 3 and Stairs 4.

But the way I tried to do it:

stairsParent.transform.parent = GenerateStairsUnits.Unit.transform;

Don't put each Stairs under Stairs 0,1,2,3,4

So what I can see is your instantiating 5 Stairs each containing the class that instantiates more stairs. In other words Stairs# is the transform the other stairs need to transform to. Your setting the other stairs currently to Stairs Unit all you need to do is the Stair# transform without .parent. Also in start remove. A quick mock up Stairs Unit/Stair# <--- transform.parent would set the other stairs to Stairs Unit what I think you are after is Stairs Unit/Stairs#/more stairs, hope that helps with the small visual.

stairsParent.transform.parent = GenerateStairsUnits.Unit.transform;

then

private IEnumerator BuildStairs()

{

    for (int i = 1; i <= stairsNumber; i++)

    {



        stairsPosition = new Vector3(

                stairsStartPosition.x,

                stairsStartPosition.y + (i * stairsSize.y),

                stairsStartPosition.z + (i * stairsSize.y) * stepWidthFactor);



        GameObject stair = Instantiate(

                stairsPrefab,

                stairsPosition,

                Quaternion.identity);



        stair.tag = "Stair";

        stair.SetParent(transform);//just use this transform I believe this would be Stairs#

        stair.transform.localScale = stairSize;



        yield return new WaitForSeconds(delay);

    }



    stairsParent.AddComponent<MoveObjects>().Init();

}