ElggMenuItem::addChild PHP Method

    public function addChild($item)
    {
        $this->data['children'][] = $item;
    }

function gvtheme_init()
{
    // custom topbar
    elgg_unregister_menu_item('topbar', 'elgg_logo');
    elgg_register_plugin_hook_handler('register', 'menu:topbar', 'gvtheme_custom_topbarmenu_setup');
    elgg_register_plugin_hook_handler('register', 'menu:entity', 'gvtheme_custom_entitymenu_setup');
    elgg_register_plugin_hook_handler('register', 'menu:river', 'gvtheme_custom_rivermenu_setup');
    elgg_register_event_handler('pagesetup', 'system', 'gvtheme_custom_usersettings_pagesetup');
    elgg_extend_view('css/elgg', 'gvtheme/css');
    elgg_extend_view('page/elements/head', 'gvtheme/head');
    // remove entities statistics views from user account
    elgg_unextend_view('core/settings/statistics', 'core/settings/statistics/numentities');
    // override some actions
    $action_base = elgg_get_plugins_path() . 'gvtheme/actions';
    elgg_register_action("avatar/upload", "{$action_base}/avatar/upload.php");
    elgg_register_action("avatar/crop", "{$action_base}/avatar/crop.php");
    elgg_register_action("friends/add", "{$action_base}/friends/add.php");
    // get number of users
    $num_members = get_number_users();
    elgg_register_menu_item('topbar', array('name' => 'member_number', 'href' => "members/newest", 'text' => elgg_echo("gvtheme:num_members", array($num_members)), 'priority' => 1000, 'section' => 'alt'));
    $initiatives_item = new ElggMenuItem('initiatives', elgg_echo('gvtheme:initiatives'));
    $cnc_item = new ElggMenuItem('cnc', elgg_echo('gvtheme:cnc'), 'file/group/9545/all');
    $cnc_item->setItemClass('gvgroup-child-menu');
    $initiatives_item->addChild($cnc_item);
    elgg_register_menu_item('site', $initiatives_item);
}