Filter by featured products in wp-admin when using WooCommerce

functions.php

add_action('restrict_manage_posts', 'featured_products_sorting');
function featured_products_sorting() {
    global $typenow;
    $post_type = 'product'; // change to your post type
    $taxonomy  = 'product_visibility'; // change to your taxonomy
    if ($typenow == $post_type) {
        $selected      = isset($_GET[$taxonomy]) ? $_GET[$taxonomy] : '';
        $info_taxonomy = get_taxonomy($taxonomy);
        wp_dropdown_categories(array(
            'show_option_all' => __("Show all {$info_taxonomy->label}"),
            'taxonomy'        => $taxonomy,
            'name'            => $taxonomy,
            'orderby'         => 'name',
            'selected'        => $selected,
            'show_count'      => true,
            'hide_empty'      => true,
        ));
    };
}
add_filter('parse_query', 'featured_products_sorting_query');
function featured_products_sorting_query($query) {
    global $pagenow;
    $post_type = 'product'; // change to your post type
    $taxonomy  = 'product_visibility'; // change to your taxonomy
    $q_vars    = &$query->query_vars;
    if ( $pagenow == 'edit.php' && isset($q_vars['post_type']) && $q_vars['post_type'] == $post_type && isset($q_vars[$taxonomy]) && is_numeric($q_vars[$taxonomy]) && $q_vars[$taxonomy] != 0 ) {
        $term = get_term_by('id', $q_vars[$taxonomy], $taxonomy);
        $q_vars[$taxonomy] = $term->slug;
    }
}

https://stackoverflow.com/questions/46470206/woocommerce-filter-by-featured-products-in-admin/46476108#46476108