Duplicating a group allows you to easily create similar Security Groups. To duplicate a group, use the File tab→Security→Security Group Definitions command. Select the group to be copied, and click the Duplicate button. A new group will be created which has the same name as the original group, but with the "(copy)" added to it.

 

You can then select the new group, click the Modify button, rename it, describe it, and set the exact permissions you need.