The Offset button creates a displacement copy of the selected object a parallel distance away as specified in the Offset Reveal field.
If it doesn’t Offset in the expected direction, click Undo and click the other Offset Direction.
The Left < button will offset an enclosed object to the outside.
The Right > button will offset an enclosed object to the inside.
Click on the desired object.
Enter the desired offset amount in the Offset Reveal field.