acls
Although the acls module can manage unix-level permissions, it provides finer-grained permission control if ACL support is enabled. Besides, volumes have to be mounted with the acl option. To do so, select the volume and toggle its ACL feature.
The volume will stand out as supporting ACLs.
If you wish to return to no ACL support, toggle the volume again.

Select a file

Pressing ACLs will display the current set of permissions, Access Control Lists..

Users and groups can be added and the corresponding permissions set (r=read,w=write,x=execute).

The settings are not effective until the Apply button is pressed.

The modify option will only add the users without modifying other settings

The user selection panel. Multiple selection is possible.

Select a folder.

The first tab refers to the actual permissions on the folder.

Users and groups can be added and the corresponding permissions set (r=read,w=write,x=execute).

The settings are not effective until the Apply button is pressed.

The modify option will only add the users without modifying other settings.

The recurse button is used to apply the settings recursively

The second tab refers to the yet-to-be-created files and folders (within the current folder), these will inherit the permissions displayed on this page.

By pressing the Diff button the two tabbed pages are compared and the differing access control are marked to the right of the rwx columns. Here, w means the write permissions differ in the actual and default pages. + would mean the line cannot be found in the other page.

The Copy button will copy the selected tab's settings to the unselected page.

This option provide a text form to the ACLs.