There is no feature in the theme for this and so this’ll be a customization you’ll need to make to the theme. You can find where the theme displays the primary navigation called “themeblvd_header_menu_default” located here within the parent theme:
Here is where you’ll find the call to wp_nav_menu. You’d need to register your own nav menus from your Child theme’s functions.php and display them based on your criteria with different instances of wp_nav_menu (this is one possible way, anyway).
To edit themeblvd_header_menu_default from your Child theme, you can either do it this way — http://dev.themeblvd.com/tutorial/editing-framework-functions/
Or you can hook your own function to “themeblvd_header_menu” — http://dev.themeblvd.com/tutorial/primary-framework-action-hooks/