private MyObject target;
private SerializedObject so;

private int viewType = 0;
private Action[] views;
private string[] names;

void OnEnable() { // или тут Awake
 views = new Action[] { ShowView1, ShowView2 };
 names = new string[] { " View #1", "View #2" };
 viewType = 0;
}

private void OnGUI() {
 GUILayout.BeginHorizontal();
 {
  for (int i=0; i<names.Length; i++)
   if (GUILayout.Button(names[i]))
    viewType = i;
 }
 GUILayout.EndHorizontal();
 var o = (MyObject) EditorGUILayout.ObjectField("rootObject", target, typeof(MyObject), true);
 if (o!= target) Init(o);
 if (target != null)
  views[viewType].Invoke();
}

private void Init(MyObject obj) {
 target = obj;
 so = new SerializedObject(target);
}

private void ShowView1() {
 Property1View1();
 Property2View1();
 Property3View1();
}

private void ShowView2() {
 Property1View2();
 Property2View2();
 Property3View2();
}