Yoast Breadcrumbs Inject Multiple Levels

My quick and dirty solution was to nest 2 arrays and loop through them. You’ll need to hard-code your nth level URLs. This example singles out a specific custom post type.

function yoast_seo_breadcrumb_append_link( $links ) { 
global $post;    
if ((is_singular('team-members'))) {
            $breadcrumbs[] = array(
                array(
                    'url' => site_url('/our-firm/'),
                    'text' => 'Our Firm'
                ),
                array(
                    'url' => site_url('/our-firm/our-professionals/'),
                    'text' => 'Our Professionals'
                )
            );
            foreach ($breadcrumbs as $breadcrumb) {
                array_splice($links, 1, -2, $breadcrumb);
            }
        }
return $links;
}