load('flexslider-example', new MenuTreeParameters()); // Build the menu render array. $fs_menu = Drupal::service('toolbar.menu_tree')->build($fs_tree); $items['flexslider_examples'] = [ '#type' => 'toolbar_item', 'tab' => [ '#type' => 'link', '#title' => t('FlexSlider Examples'), '#url' => Url::fromRoute(''), '#attributes' => [ 'title' => t('FlexSlider examples menu'), 'class' => ['toolbar-icon', 'toolbar-icon-menu'], ], ], 'tray' => [ '#heading' => t('FlexSlider examples menu'), 'flexslider_example_menu' => $fs_menu, ], '#weight' => 99, ]; return $items; }