I’m using this function to switch to my main website’s navigation and display it on all sub sites in my multisite network. Ideally the links should have the following format:

http://www.mysite.com/navigation-link

but on the sub-sites the urls are http://www.mysite.com/subsite/navigation-link

Obviously these pages don’t exist so it’s just showing a blank page. Any idea how I could make sure the urls are like the first example and how I might incorporate that into my function?

function wp_multisite_nav_menu() {

    global $blog_id;

    $args = array(
            'menu' => 'Main Menu',
            'theme_location' => 'main-nav'

        );

    $main_blog = 1; 

    $main_blog = absint( $main_blog );


    if ( !is_multisite() || $blog_id == $main_blog ) {
        echo wp_nav_menu( $args );
        return;
    }

    else {

    switch_to_blog( 1 );

    echo wp_nav_menu( $args );

    restore_current_blog();

    }

}