Click the icon and then click on any control point of any surface in one of the orthogonal projection views. All the control points of the surface corresponding to the clicked point will be highlighted in red. Drag the mouse across the screen and release it when you reach the desired position.

Other surfaces can be added incrementally to the drag operation. Individual control points can be removed from the drag operation by clicking with the CTRL key pressed.

The information box (above the 3D view) displays information about the drag distance.

Switch between orthogonal projection views and continue dragging.