Test

<?php
$items = (new \Bitrix\Main\Entity\Query(Bitrix\Iblock\ElementTable::getEntity()))
    ->setSelect([
        'ID',
        'CODE',
        'NAME',
        'BRAND_ID'   => 'PROPERPTY.VALUE',
        'BRAND_PROP_' => 'BRAND_PROP.VALUE'
    ])
    ->registerRuntimeField(
        'PROPERPTY',
        [
            'data_type' => Bitrix\Iblock\ElementPropertyTable::class,
            'reference' =>
                [
                    '=this.ID' => 'ref.IBLOCK_ELEMENT_ID',
                ],
        ]
    )
    ->registerRuntimeField(
        'BRAND',
        [
            'data_type' => \Bitrix\Iblock\ElementTable::class,
            'reference' =>
                [
                    '=this.PROPERPTY.VALUE' => 'ref.ID'
                ]
        ]
    )
    ->registerRuntimeField(
        'BRAND_PROP',
        [
            'data_type' => Bitrix\Iblock\ElementPropertyTable::class,
            'reference' =>
                [
                    '=this.BRAND.ID' => 'ref.IBLOCK_ELEMENT_ID',
                ],
        ]
    )
    ->setFilter([
        '=IBLOCK_ID'                    => PRODUCT_IBLOCK_ID,
        '=ACTIVE'                       => 'Y',
        '=PROPERPTY.IBLOCK_PROPERTY_ID' => PROP_MANUFACTURER
    ])
    ->exec()
    ->fetchAll();