Add a Link to Yoast SEO Breadcrumbs

Say you want to add a link to the blog in the Yoast breadcrumbs after the initial link to the home page. You can do this by adding the following code to your functions.php file:

function yoast_seo_breadcrumb_append_link( $links ) {
    global $post;
        $breadcrumb[] = array(
            'url' => site_url( '/blog/' ),
            'text' => 'Blog',
        );
        array_splice( $links, 1, -2, $breadcrumb );
    return $links;
}
add_filter( 'wpseo_breadcrumb_links', 'yoast_seo_breadcrumb_append_link' );

Here is a broader article on how to add breadcrumbs to WordPress sites…