Transform a gameobject y rotation to another gameobject y rotation

You can simply assign Rotation of one object to other as:

• Make Two gameObjects.

• Copy the eulerAngles Of one gameObject and save into local variable.

• Rotate your Object x and z axis as it is and change Y which you save into your local variable as in the script.

   public GameObject ObjA;
           public GameObject ObjB;
           private void Start()
           {
               var yRotation = ObjB.transform.eulerAngles.y;
               ObjA.transform.Rotate(ObjA.transform.eulerAngles.x, yRotation, ObjA.transform.eulerAngles.z);
           }