This dialog can be reached via the Administration tab of the details view. Use it to specify which user groups should have a specific permission for the currently selected file.
In order to grant a user group the permission specified in the dialog enter the name or a part of it into the Group input field and click the search button (magnifying glass). You can also leave the input field empty.
When selecting a user group, if more than one user group match the characters entered into the input field, these groups will be listed in a selection dialog. If the input field was empty, all groups that can be selected (and have not been assigned yet) are listed:
Select the groups you would like to grant the permission concerned and return to the assignment dialog by clicking OK . To revoke the permission concerned from one or more groups, select them in the group list and click Remove . Click OK to grant the listed groups the permission concerned.