Wenn man bspw. vis PHP nach dem Header eine Zeile mit TItel und Breadcrumb einfügt…
Showing User’s „custom POst Types“ instead of just regular „posts“ in the Admin’s User table
add_action('manage_users_columns','yoursite_manage_users_columns');
function yoursite_manage_users_columns($column_headers) {
    unset($column_headers['posts']);
    $column_headers['custom_posts'] = 'Assets';
    return $column_headers;
}
add_action('manage_users_custom_column','yoursite_manage_users_custom_column',10,3);
function yoursite_manage_users_custom_column($custom_column,$column_name,$user_id) {
    if ($column_name=='custom_posts') {
        $counts = _yoursite_get_author_post_type_counts();
        $custom_column = array();
        if (isset($counts[$user_id]) && is_array($counts[$user_id]))
            foreach($counts[$user_id] as $count) {
                $link = admin_url() . "edit.php?post_type=" . $count['type']. "&author=".$user_id;
                // admin_url() . "edit.php?author=" . $user->ID;
                $custom_column[] = "\t<tr><th><a href={$link}>{$count['label']}</a></th><td>{$count['count']}</td></tr>";
            }
        $custom_column = implode("\n",$custom_column);
        if (empty($custom_column))
            $custom_column = "<th>[none]</th>";
        $custom_column = "<table>\n{$custom_column}\n</table>";
    }
    return $custom_column;
}
function _yoursite_get_author_post_type_counts() {
    static $counts;
    if (!isset($counts)) {
        global $wpdb;
        global $wp_post_types;
        $sql = <<<SQL
        SELECT
        post_type,
        post_author,
        COUNT(*) AS post_count
        FROM
        {$wpdb->posts}
        WHERE 1=1
        AND post_type NOT IN ('revision','nav_menu_item')
        AND post_status IN ('publish','pending', 'draft')
        GROUP BY
        post_type,
        post_author
SQL;
        $posts = $wpdb->get_results($sql);
        foreach($posts as $post) {
            $post_type_object = $wp_post_types[$post_type = $post->post_type];
            if (!empty($post_type_object->label))
                $label = $post_type_object->label;
            else if (!empty($post_type_object->labels->name))
                $label = $post_type_object->labels->name;
            else
                $label = ucfirst(str_replace(array('-','_'),' ',$post_type));
            if (!isset($counts[$post_author = $post->post_author]))
                $counts[$post_author] = array();
            $counts[$post_author][] = array(
                'label' => $label,
                'count' => $post->post_count,
                'type' => $post->post_type,
                );
        }
    }
    return $counts;
}
