Freestyle > Adding Detail to the Control Mesh > To Duplicate Mesh Elements
  
To Duplicate Mesh Elements
Use the Duplicate option to create a copy of a face, a loop of faces or edges, or an entire shape.
1. Create or import a shape.
2. Select one or more faces, loop of faces or edges, or an entire shape.
3. Click Freestyle > Duplicate. Alternatively, right-click and select Duplicate. A new shape with the same control mesh as of the selected faces or edges is created at the same location in the coordinate system.