I have a subsite to the main which has unique permissions. I've added an Owner to this subsite, who will help administer permissions. I've given them the same access on the subsite that I have (I'm the admin for the main and all subsites), but they cannot edit permissions. On the main site, they have View Only permissions. Is this the problem, and if so, how can I modify without giving them Owner access to the main site?

Thank you

Hi,

As I tested in my environment, subsite owner has permission to add users to permission group, however, the account has no permission to add or edit permission level. Permission level can be added or edited from site collection level at least.

If you need to assign Edit Permission to subsite owner, please go to Site collection site settings > Site Permissions > Permission Levels > Add a Permission Level, give it a name and scroll down to Site Permissions > Manage Permissions.

Once you check this option, there are some other options checked automatically. Then add subsite owner to this level.

Now if you login as subsite owner to subsite site settings > site permissions > permission levels, there will be an option "Manage Permission Levels on Parent Web Site". You can edit permissions there.

Regards,