@all: Ubuntu user interface is not able to do that yet. Here is a easy work around for those who don't use command line.
STEPS
Installing 'PCMan File Manager' from the repositories. It's a sweet little lightweight file manager (ordinarily part of the LXDE desktop, but it's modular).
Navigate to the following Ubuntu's menu APPLICATIONS > SYSTEM TOOL > PCMAN FILE MANAGER
Navigate to the folder you want to edit the permissions. Select the folder with one left click.
Navigate to the following PCMAN FILE MANAGER's menu TOOL > OPEN CURRENT FOLDER AS ROOT.
Navigate to the following PCMAN FILE MANAGER's menu FILE > FILE PROPERTIES
Type in the OWNER
Type in the GROUP
Choose permissions for all the files in that folder.
Make sure SET UID and SET GID boxes are checked.
Note: UID stands for USER ID. GID stands for GROUP ID. Do not check STICKY unless you know what you're doing.
Click on OK button.
PCMAN FILE MANAGER will ask if 'Do you want to recursively apply these changes to all files and sub-folders?' This is what you want to do so click on YES button.
That's it. You have successfully changed all files and sub-folders permissions.
@all: Ubuntu user interface is not able to do that yet. Here is a easy work around for those who don't use command line.
STEPS
Installing 'PCMan File Manager' from the repositories. It's a sweet little lightweight file manager (ordinarily part of the LXDE desktop, but it's modular).
Navigate to the following Ubuntu's menu APPLICATIONS > SYSTEM TOOL > PCMAN FILE MANAGER
Navigate to the folder you want to edit the permissions. Select the folder with one left click.
Navigate to the following PCMAN FILE MANAGER's menu TOOL > OPEN CURRENT FOLDER AS ROOT.
Navigate to the following PCMAN FILE MANAGER's menu FILE > FILE PROPERTIES
Type in the OWNER
Type in the GROUP
Choose permissions for all the files in that folder.
Make sure SET UID and SET GID boxes are checked.
Note: UID stands for USER ID. GID stands for GROUP ID. Do not check STICKY unless you know what you're doing.
Click on OK button.
PCMAN FILE MANAGER will ask if 'Do you want to recursively apply these changes to all files and sub-folders?' This is what you want to do so click on YES button.
That's it. You have successfully changed all files and sub-folders permissions.