We have Multi-Site enabled for our several branch locations and most have a local IT admin. For security reasons they are not SuperAdmins. However, we still give them certain permissions to update user extension settings and groups. We have done this by giving them the User Management role permissions and limiting the site to only their site. However, these permissions do not seems to apply to paging groups. If I remove the site restriction, they can see all sites and then they can add or remove extensions as needed to the paging group. But when restricted again to only their site, they get an error: "Mailbox has no permission to this action."
After working with RC support for several weeks, they suggested I submit a feature request for this.