SelectionMode can be used to tweak the selection returned by Selection.GetTransforms.
The default transform selection mode is: SelectionMode.TopLevel | SelectionMode.ExcludePrefab | SelectionMode.Editable.
| Unfiltered | Return the whole selection. |
| TopLevel | Only return the topmost selected transform. A selected child of another selected transform will be filtered out. |
| Deep | Return the selection and all child transforms of the selection. |
| ExcludePrefab | Excludes any prefabs from the selection. |
| Editable | Excludes any objects which shall not be modified. |
| Assets | Only return objects that are assets in the Asset directory. |
| DeepAssets | If the selection contains folders, also include all assets and subfolders within that folder in the file hierarchy. |