Step 1 : When you click on Class Groups Sub-module under Academic Settings Module below window will be shown. Here you can manage Class Groups.

Step 2 : On the top right hand corner, Add New Group button is available which can be used for adding new Class Groups.

Step 3 : And when you click on Add New  Group below window will popup on your screen. Here you can add new Class Groups.

Step 4 : After Saving, the new Group list will show where you can Modify & Delete Class Groups. All action button will show in below Figure.