The offset tool in SketchUp (keyboard shortcut F) is used to duplicate a perimeter with the spacing specified. This tool can not be used with components. It is only used in model space when drawing.
To start the offset command press F on the keyboard or select the offset button from the toolbar. Then click on a perimeter that is already created in model space. From there you can drag your mouse on either side of the perimeter to duplicate the shape. Type in the dimension you wish to offset your new perimeter and press enter on the keyboard.