User with the Administrator Role can access to all Sites/Documents & Media in the Control Panel, but not in the CKEditor File Browser, so, he can't create WebContent and link documents that he is allowed to manage.
Steps to reproduce:
As test / superadmin:
1. Create an Organization, Org1.
2. Edit Org1 and create the Org1 site.
3. Create another Site, Site1.
4. Create an user3, and set Regular Role: Administrator.
5. Go to Control Panel > Sites: User1 can access to all sites, including Org1 and Site1, also can access to Documents & Media Library of the Sites.
6. Go to Control Panel > Sites > Org1 > Content: Web Content, and add a new content.
7. Click on the Image button of the rich text editor and Browse Server.
Result: user3 (Administrator) can't access to the root folder of Org1. See user3.png.
Expected: user3 (Administrator) can access to all the root folders.
If you add user3 as member of Org1 or any Site, you are allowed to view the root folder, however, an administrator doesn't need to be member of a Organization or Site to access to any resource.