This template takes advantage of the exclusive YOOtheme Accordion Menu for the sub level navigation. The Accordion Menu uses mootools for the transition effect with smooth animation and color fading.
For example take a look at the left/right and click on the arrows in the submenu to open the next menu level.
To setup the Accordion Menu do the following.
Create a new menu item for level 2 (this means a new item for the sub menu). Choose under "Miscellaneous" the "Separator/Placeholder" option.
Next create new menu items in level 3 (this means the sub level of the new "Separator/Placeholder"). For example take a look.