\Bitrix\Main\Loader::includeModule('sale');
$date = new \Bitrix\Main\Type\Date();
$date->add('-2 year');
$userDataByOrders = \Bitrix\Sale\Order::getList([
'filter' => ['>DATE_INSERT' => $date->toString()],
'select' => ['USER_ID', 'USER_INFO_' => 'USER'],
'group' => ['USER_ID']
]);
$userData = $userDataByOrders->fetchAll();