Select Edit > Flip Design and select Vertical or Horizontal from the dropdown control. The entire design will be flipped in the direction selected.

Have the design on the screen. 

Select Edit > Flip Design > Horizontal/Vertical to flip the entire design horizontally or vertically.  

The entire design is flipped over in the direction selected.

Optionally, use the Flip button to flip the selected objects over horizontally or vertically.

This allows you to manually select which objects to Flip instead of flipping the entire design. 

Optionally, use the Mirror button to make a mirror copy of the selected objects.

This will allow you to manually select the desired objects that will be mirrored along the axis line.