You must have "Full Access" or "Limited Access - HQ Tools" permissions to give a group permissions.
Sign in and turn on Edit Mode.
Go to the page on your site where you want to add the group.
Click on the Permissions sub-tab.
NOTE: If you are on a League, Division, or Team page, click on Admin > Permissions.
Scroll down and under Group Permissions, click Add Group.
You need to have a group created before adding a group.
Search or select a group.
After the group is highlighted, give them "Owner," "Edit," or "View" permissions to the page.
Owner: Update and edit all content, move or delete pages, assign permissions, create groups, send messages, create new pages, etc.
Edit: View private page, add elements, and edit content.
View: View private page.
Click Add Groups.