Undoing and Redoing Operations
It is possible to undo the last operation for operations like adding, disabling, moving, and deleting nodes in the Model Builder as well as changing values in the Settings window. You can undo or redo several successive operations.
To undo the last operation or redo an undone operation:
On the Quick Access Toolbar (Windows users) or from the main Edit menu (macOS and Linux users), select or click Undo () or Redo ().