productfilter.php

См. документацию.

<?php
 
namespace Bitrix\Catalog\Filter;
 
use Bitrix\Main;
 
class ProductFilter extends Main\Filter\Filter
{
    protected function removeServiceUiFilterFields(array &$filter): void
    {
        parent::removeServiceUiFilterFields($filter);
        if (
            !empty($filter['SUBQUERY']['FILTER'])
            && is_array($filter['SUBQUERY']['FILTER'])
        )
        {
            parent::removeServiceUiFilterFields($filter['SUBQUERY']['FILTER']);
        }
    }
}