Click on this button after selecting more than one control point to place the selected control points into a group. All control points that are added into a group will obtain the same enhancement slider settings. Groups act in a similar fashion to control points, except where a control point bases its selection off of a single color and tonal value, groups can use multiple values to create a more precise selection. A group of control points share a single set of enhancement sliders and apply the same enhancement effect to their selected objects.
After adding control points into a group, the icon for the control points will change, with the enhancement sliders being presented only on one control point. The size slider for each control point in a group however can be adjusted independently.
Group Control Points: Ctrl (Windows) / Command (Macintosh) + G