Adding multiple menus to Joomla has generally been very flexible once you get the hang of it, but overall, very easy.
If you see the screenshot of the demo site (to the right), you will see the submenu which is located on a full width light grey bar – which incidently includes the breadcrumb navigation off to the left of it.
To get this menu, you have to create a new menu:
01Go to your Menu Manager and create a new Menu group
02Create your menu items
03Open the menu module from the Module Manager
04Publish the module to the “Submenu” position (don’t show title)
05Set your menu style as “Legacy – Flat List“
06Set your menu class suffix as “-nav” (without the quotes) click SAVE
If all goes well, your menu should appear in the breadcrumbs pathway like the screenshot shown here.