Tier 3 menu creation

Hi ..
       In my application The Top Menu is my Main menu and the Left menu is the Sub menus of main menu . Now i need a Popup menus for sub menus of Sub menu . Is there any possibilities to create popup menus or sub menus of sub menu

Ex: Tier1 - Money Fact ---- > Main menu (top menu)
       Tier2 - Real Estate ----> Sub menu of Money Fact (Left menu )
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     Tier3 -
Getting started
        Ownership
                  These are my Sub menus of Real estate menu .I need to display this menus as popup menus .

Is there any option to display these menus Let me know .

Thank you