How delegating group management? (for Jira administrator)
1) Open url in you Jira '/secure/jibrokDelegatingGroupManagementAdminPanel!default.jspa' or open admin search (gg) and find 'Settings for Delegating Group Management'
2) Click '+ Add group delegating'
3) Select the users or groups(admins) you want to grant group management rights to.
4) Select the groups(delegating) that the users listed above will manage.
5) Click 'Ok'
How to manage groups (for Jira users)
1) Open url in your Jira '/secure/jibrokDelegatingGroupManagementUserPanel!default.jspa' or open click in user menu 'Group management'
2) Select a group and manage its users