Enabling advance file permission in Ubuntu or other Linux distribution helps you to set a privillege to the different users based on the orginal UNIX permission model(rwxr xr r). It is not enable by default in Ubuntu. You can use Chmod command which will help to change the file or directory permission but incase for the user who don’t like to mess with command and want simple GUI to perform this task can use the following command to enable in ubuntu or other Linux distribution.
Note : Make sure you are using Nautilus.
Open terminal(CTRL+ALT+T) and run the following command.
gsettings set org.gnome.nautilus.preferences show-advanced-permissions true
The command will set the show-advanced-permission to true which will enable advance file permission in your computer.
After enabling it Right click on any folder of file go to properties –> permission. You will see the following changes.
you can simply roll back to previous file permission interface by the use following command
gsettings set org.gnome.nautilus.preferences show-advanced-permissions false
The above command will set the show-advance-permissions to false. You will be roll back to your previous interface.
Note: Setting file permission without the proper knowledge can be vulnerable for your system. Therefore I urge you to understand the file permission system before setting permission to any file or directory.