Acess 1st degree children and the same components in them and children inside of the children?

If you have an EnemyManager script which handles the spawning of the enemies, you should collect them into an array of GameObjects. For accessing the components of the enemies, you can use:

 foreach(GameObject enemy in enemies)
 {
     enemy.GetComponent<Type>().enabled = false;
 }

For accessing the children of the enemies, you can use:

 foreach(GameObject enemy in enemies)
 {
     enemy.transform.GetChild(0).gameObject.SetActive(false);
     enemy.transform.GetChild(1).gameObject.SetActive(false);
 }

The 0 and 1 integer parameter represents the number of the child in the hierarchy (so 0 refers to the 1st child, 1 refers to the 2nd child, etc). The 'enemies' variable represent the GameObject array.

If you're looking for specific components, just use GetComponentsInChildren. It's recursive, so it's going to find all the components inside that hierarchy.

For example, say that the component you want to turn off is called Enemy, then you could do:

 Enemy [] enemies = enemiesParent.GetComponentsInChildren<Enemy>();
 foreach (Enemy enemy in enemies)
     enemy.gameObject.SetActive(false);