Hi, there, I am new to OwnCloud, currently working for a small business.
My supervisor told me in his previous experience in other company, the admin user can check who have access to a shared folder.
For example, me as an admin, Ben as an employee create a folder - internal files then share it with me and some others, am I be able to see who are those people that also have access to this folder.
Only the owner of the file/folder can see that. As Admin you are not supposed to see any data from your users. Of course if you like you can install the impersonate app which will allow you to login as another user as admin and see for yourself.
In the Enterprise Version via Logging/Audit you would see with tools like Splunk/Kibana what was going on and then there is a partner who has an extension called Sharing Cockpit which provides some of this functionality. If this is of interest please contact us.