Question Selecting/Moving both tiles and gameobjects with one brush via Tile Palette tools... is it possible?

You could try this custom brush script which combines both the Default Brush and the GameObject Brush:

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Tilemaps;
3.  
4. namespace UnityEditor.Tilemaps
5. {
6.     [CustomGridBrush(true, false, false, "Default+GameObject Brush")]
7.     public class DefaultGameObjectBrush : GridBrush
8.     {
9.         [SerializeField]
10.         internal GridBrushBase[] gridBrushes;
11.  
12.         public void ValidateBrushes()
13.         {
14.             if (gridBrushes == null
15.                 || gridBrushes.Length == 0
16.                 || gridBrushes[0] == null)
17.             {
18.                 gridBrushes = new GridBrushBase[2];
19.                 gridBrushes[0] = ScriptableObject.CreateInstance<GridBrush>();
20.                 gridBrushes[1] = ScriptableObject.CreateInstance<GameObjectBrush>();
21.             }
22.         }
23.        
24.         public override void Select(GridLayout gridLayout, GameObject brushTarget, BoundsInt position)
25.         {
26.             ValidateBrushes();
27.             for (int i = 0; i < gridBrushes.Length; ++i)
28.                 gridBrushes[i].Select(gridLayout, brushTarget, position);
29.         }
30.  
31.         public override void Move(GridLayout gridLayout, GameObject brushTarget, BoundsInt from, BoundsInt to)
32.         {
33.             ValidateBrushes();
34.             for (int i = 0; i < gridBrushes.Length; ++i)
35.                 gridBrushes[i].Move(gridLayout, brushTarget, from, to);
36.         }
37.  
38.         public override void MoveStart(GridLayout gridLayout, GameObject brushTarget, BoundsInt position)
39.         {
40.             ValidateBrushes();
41.             for (int i = 0; i < gridBrushes.Length; ++i)
42.                 gridBrushes[i].MoveStart(gridLayout, brushTarget, position);
43.         }
44.  
45.         public override void MoveEnd(GridLayout gridLayout, GameObject brushTarget, BoundsInt position)
46.         {
47.             ValidateBrushes();
48.             for (int i = 0; i < gridBrushes.Length; ++i)
49.                 gridBrushes[i].MoveEnd(gridLayout, brushTarget, position);
50.         }
51.  
52.         public override void Paint(GridLayout gridLayout, GameObject brushTarget, Vector3Int position)
53.         {
54.             ValidateBrushes();
55.             for (int i = 0; i < gridBrushes.Length; ++i)
56.                 gridBrushes[i].Paint(gridLayout, brushTarget, position);
57.         }
58.  
59.         public override void Erase(GridLayout gridLayout, GameObject brushTarget, Vector3Int position)
60.         {
61.             ValidateBrushes();
62.             for (int i = 0; i < gridBrushes.Length; ++i)
63.                 gridBrushes[i].Erase(gridLayout, brushTarget, position);
64.         }
65.  
66.         public override void Pick(GridLayout gridLayout, GameObject brushTarget, BoundsInt position, Vector3Int pickStart)
67.         {
68.             ValidateBrushes();
69.             for (int i = 0; i < gridBrushes.Length; ++i)
70.                 gridBrushes[i].Pick(gridLayout, brushTarget, position, pickStart);
71.             base.Pick(gridLayout, brushTarget, position, pickStart);
72.         }
73.  
74.         public override void FloodFill(GridLayout gridLayout, GameObject brushTarget, Vector3Int position)
75.         {
76.             ValidateBrushes();
77.             for (int i = 0; i < gridBrushes.Length; ++i)
78.                 gridBrushes[i].FloodFill(gridLayout, brushTarget, position);
79.         }
80.  
81.         public override void BoxFill(GridLayout gridLayout, GameObject brushTarget, BoundsInt position)
82.         {
83.             ValidateBrushes();
84.             for (int i = 0; i < gridBrushes.Length; ++i)
85.                 gridBrushes[i].BoxFill(gridLayout, brushTarget, position);
86.         }
87.  
88.         public override void Flip(FlipAxis flip, GridLayout.CellLayout layout)
89.         {
90.             ValidateBrushes();
91.             foreach (var gridBrush in gridBrushes)
92.             {
93.                 gridBrush.Flip(flip, layout);
94.             }
95.         }
96.  
97.         public override void Rotate(RotationDirection direction, GridLayout.CellLayout layout)
98.         {
99.             ValidateBrushes();
100.             foreach (var gridBrush in gridBrushes)
101.             {
102.                 gridBrush.Rotate(direction, layout);
103.             }
104.         }
105.  
106.         public override void ChangeZPosition(int change)
107.         {
108.             ValidateBrushes();
109.             foreach (var gridBrush in gridBrushes)
110.             {
111.                 gridBrush.ChangeZPosition(change);
112.             }
113.         }
114.  
115.         public override void ResetZPosition()
116.         {
117.             ValidateBrushes();
118.             foreach (var gridBrush in gridBrushes)
119.             {
120.                 gridBrush.ResetZPosition();
121.             }
122.         }
123.     }
124.  
125.     /// <summary>
126.     /// The Brush Editor for a Layer Brush.
127.     /// </summary>
128.     [CustomEditor(typeof(DefaultGameObjectBrush))]
129.     public class DefaultGameObjectBrushEditor : GridBrushEditor
130.     {
131.         public DefaultGameObjectBrush targetBrush
132.         {
133.             get
134.             {
135.                 return target as DefaultGameObjectBrush;
136.             }
137.         }
138.  
139.         private GridBrushEditorBase[] editors;
140.  
141.         private void CreateEditor()
142.         {
143.             targetBrush.ValidateBrushes();
144.             if (targetBrush.gridBrushes != null
145.                 && (editors == null
146.                 || editors.Length != targetBrush.gridBrushes.Length
147.                 || editors[0] == null))
148.             {
149.                 editors = new GridBrushEditorBase[targetBrush.gridBrushes.Length];
150.                 for (int i = 0; i < editors.Length; ++i)
151.                 {
152.                     editors[i] = Editor.CreateEditor(targetBrush.gridBrushes[i]) as GridBrushEditorBase;
153.                 }
154.             }
155.         }
156.  
157.         public override void RegisterUndo(GameObject brushTarget, GridBrushBase.Tool tool)
158.         {
159.             var undoObjects = new UnityEngine.Object[2];
160.             undoObjects[0] = brushTarget;
161.             undoObjects[1] = brushTarget.GetComponent<Tilemap>();
162.             Undo.RegisterCompleteObjectUndo(undoObjects, tool.ToString());
163.         }
164.  
165.         public override void OnPaintSceneGUI(GridLayout gridLayout, GameObject brushTarget, BoundsInt position,
166.             GridBrushBase.Tool tool, bool executing)
167.         {
168.             CreateEditor();
169.             for (int i = 0; i < editors.Length; ++i)
170.             {
171.                 editors[i].OnPaintSceneGUI(gridLayout, brushTarget, position, tool, executing);
172.             }
173.         }
174.  
175.         public override void PaintPreview(GridLayout gridLayout, GameObject brushTarget, Vector3Int position)
176.         {
177.             CreateEditor();
178.             for (int i = 0; i < editors.Length; ++i)
179.             {
180.                 var editor = editors[i] as GridBrushEditor;
181.                 if (editor != null)
182.                     editor.PaintPreview(gridLayout, brushTarget, position);
183.             }
184.         }
185.  
186.         public override void BoxFillPreview(GridLayout gridLayout, GameObject brushTarget, BoundsInt position)
187.         {
188.             CreateEditor();
189.             for (int i = 0; i < editors.Length; ++i)
190.             {
191.                 var editor = editors[i] as GridBrushEditor;
192.                 if (editor != null)
193.                     editor.BoxFillPreview(gridLayout, brushTarget, position);
194.             }
195.         }
196.  
197.         public override void FloodFillPreview(GridLayout gridLayout, GameObject brushTarget, Vector3Int position)
198.         {
199.             CreateEditor();
200.             for (int i = 0; i < editors.Length; ++i)
201.             {
202.                 var editor = editors[i] as GridBrushEditor;
203.                 if (editor != null)
204.                     editor.FloodFillPreview(gridLayout, brushTarget, position);
205.             }
206.         }
207.  
208.         public override void ClearPreview()
209.         {
210.             CreateEditor();
211.             if (editors != null)
212.             {
213.                 foreach (var editor in editors)
214.                 {
215.                     var gridBrushEditor = editor as GridBrushEditor;
216.                     if (gridBrushEditor != null)
217.                         gridBrushEditor.ClearPreview();
218.                 }
219.             }
220.         }
221.     }
222. }