Как выбрать товары по условию скидки CONDITION ?

function OnDiscountAddHandler($ID, $arFields) {

    if (sizeof($arFields['PRODUCT_IDS']) > 0) {
        if ($arFields['ACTIVE'] == 'Y') {
            foreach ($arFields['PRODUCT_IDS'] as $item):
                CIBlockElement::SetPropertyValuesEx($item, 2, array('DISCOUNT' => 33));
            endforeach;
        }
        else {
            foreach ($arFields['PRODUCT_IDS'] as $item):
                CIBlockElement::SetPropertyValuesEx($item, 2, array('DISCOUNT' => false));
            endforeach;
        }
    }
    if (sizeof($arFields['SECTION_IDS']) > 0) {
        if ($arFields['ACTIVE'] == 'Y') {
            foreach ($arFields['SECTION_IDS'] as $item):
                $res = CIBlockElement::GetList([], ['IBLOCK_ID' => 2, 'SECTION_ID' => $item, 'INCLUDE_SUBSECTIONS' => 'Y'], false, false, ['ID']);
                while ($db_res = $res->Fetch())
                    CIBlockElement::SetPropertyValuesEx($db_res['ID'], 2, array('DISCOUNT' => 33));
            endforeach;
        }else {
            foreach ($arFields['SECTION_IDS'] as $item):
                $res = CIBlockElement::GetList([], ['IBLOCK_ID' => 2, 'SECTION_ID' => $item, 'INCLUDE_SUBSECTIONS' => 'Y'], false, false, ['ID']);
                while ($db_res = $res->Fetch())
                    CIBlockElement::SetPropertyValuesEx($db_res['ID'], 2, array('DISCOUNT' => false));
            endforeach;
        }
    }
}