When viewing a NetCommunity website the menus do not show the dropdown options (submenu items). They only display the top level menu item. Secondary menus do not display. If the user has rights to the admin pages of NetCommunity they only see the main menu items of the NetCommunity tool bar when viewing the web site (i.e. Edit vs Edit this page).
Additional levels of the menus must be styled using CSS in your stylesheet before they will show.
Our Website Introduction documentation covers the basics of layouts, stylesheets, templates and pages: https://www.blackbaud.com/files/support/guides/bbnc/BBNCWebsiteDesign.html