Умный фильтр Битрикс

section.php

if (CModule::IncludeModule("iblock"))
{
	$arFilter = array(
		"ACTIVE" => "Y",
		"GLOBAL_ACTIVE" => "Y",
		"IBLOCK_ID" => $arParams["IBLOCK_ID"],
	);
	if(strlen($arResult["VARIABLES"]["SECTION_CODE"])>0)
	{
		$arFilter["CODE"] = $arResult["VARIABLES"]["SECTION_CODE"];
	}
	elseif($arResult["VARIABLES"]["SECTION_ID"]>0)
	{
		$arFilter["ID"] = $arResult["VARIABLES"]["SECTION_ID"];
	}

	$obCache = new CPHPCache;
	if($obCache->InitCache(36000, serialize($arFilter), "/iblock/catalog"))
	{
		$arCurSection = $obCache->GetVars();
	}
	else
	{
		$arCurSection = array();
		$dbRes = CIBlockSection::GetList(array(), $arFilter, false, array("ID"));
		$dbRes = new CIBlockResult($dbRes);

		if(defined("BX_COMP_MANAGED_CACHE"))
		{
			global $CACHE_MANAGER;
			$CACHE_MANAGER->StartTagCache("/iblock/catalog");

			if ($arCurSection = $dbRes->GetNext())
			{
				$CACHE_MANAGER->RegisterTag("iblock_id_".$arParams["IBLOCK_ID"]);
			}
			$CACHE_MANAGER->EndTagCache();
		}
		else
		{
			if(!$arCurSection = $dbRes->GetNext())
				$arCurSection = array();
		}

		$obCache->EndDataCache($arCurSection);
	}
}

В вызове умного фильтра прописать в параметре "SECTION_ID" => $arCurSection["ID"],