When you add a site to a site group, the site cannot already belong to the site group as only one instance of a site can exist in a site group. If the site group contains shareables, the site cannot belong to any other site groups that contain the same shareables.
Open the Business Control Center.
Select Site Administration.
Select the Site Assets link.
Enter the name of a project and click Continue.
Right-click the site group to edit, and click Edit. The Site Group panel appears.
Right-click the sites you want to add to the site group, and click Add.
To add a new site to a site group, right-click the site group in the left pane and click Add Site.
Click Save to save the site group.
