Hi Tim,
There is nothing built in to MMM which would let you do that sorry. You would need to modify your theme and add in another menu, or find a theme that outputs 2 menus like it does on the site you have linked to, then enable MMM for that second menu.
Theme modifications are not something we cover through support, so it would be best to find a theme that already has the menu layout you’re looking for (or a header type builder that will let you add 2 menus).
Regards,
Tom