How to manage the 2cd level-menu of ES?

Hello

I understand there is 2 levels of menu
- a main menu at the very top of the ES page
http://newclm.com/administrator/index.php?option=com_menus&;view=items&menutype=mainmenu
- another menu, lower than the main one, in the **black menu bar** as you can see in the attached file

I would like to add new menu items on this black bar : how can I do that?

Thanks
Henri