hlblock

CModule::IncludeModule('iblock');
CModule::IncludeModule('highloadblock');

use Bitrix\Highloadblock as HL;
use Bitrix\Main\Entity;

$hlblock_id = 2;

$hlblock = HL\HighloadBlockTable::getById($hlblock_id)->fetch();

$entity = HL\HighloadBlockTable::compileEntity($hlblock);
$entity_data_class = $entity->getDataClass();

$rsData = $entity_data_class::getList(array(
   "select" => array( "ID", "UF_NAME"),
   "order" => array( ),
   "filter" => array(  )
));

while($arData = $rsData->Fetch()){
  //other code
}