How to instantiate multiple Prefabs in line and then repeat it?

Something like the below, but you have to work in your logic. Not sure if you have spawn positions/time between spawning, etc.. But this allows you to set your desired amount of prefabs and their child prefabs in the inspector (It assumes all children are the same prefab for each of the parents). It loops through the prefabs you set, spawns them, and then spawns the given children and sets the said prefab as the parent.

 [SerializeField] GameObject[] prefabs;
 [SerializeField] GameObject[] children;
 
 private void Start()
 {
     for(int i = 0; i < prefabs.length; i++)
     {
         GameObject obj = Instantiate(prefabs[i]);
         
         for(int j = 0; j < children; j++)
         {
             Instantiate(children[j], obj.transform);
         }
     }
 }