ЧПУ фильтр по доп. свойствам в ИМ на посадочной странице

                  // Товар был уже определен, по пути ищем модификацию
                  if ($this->item)
                  {
                     // ...
                  }
                  else
                  {
                     // Добавляете вместо этих строк:
                     //$this->group = FALSE;
                     //return $this->error404();
                  }

$oShop = Core_Entity::factory('Shop', Core_Array::get(Core_Page::instance()->libParams, 'shopId'));

$Shop_Controller_Show = new Shop_Controller_Show($oShop);

$on_page = intval(Core_Array::getRequest('on_page'));
if ($on_page > 0 && $on_page < 250)
{
    $Shop_Controller_Show->limit = $on_page;
    $Shop_Controller_Show->addEntity(
        Core::factory('Core_Xml_Entity')
            ->name('on_page')->value($on_page)
    );
    $Shop_Controller_Show
        ->limit($on_page)
        ->parseUrl();
}
else
{
    $Shop_Controller_Show
        ->limit($oShop->items_on_page)
        ->parseUrl();
}

Core_Page::instance()->object = $Shop_Controller_Show;

$Shop_Controller_Show = Core_Page::instance()->object;
$Shop_Controller_Show
    ->xsl(
        Core_Entity::factory('Xsl')->getByName('МагазинКаталогТоваров')
    );

$Shop_Controller_Show->addEntity(
    Core::factory('Core_Xml_Entity')
        ->name('header')->value('Акции')
);

$Shop_Controller_Show
    ->shopItems()
    ->queryBuilder()
    ->join('shop_item_discounts', 'shop_item_discounts.shop_item_id', '=', 'shop_items.id')
    ->join('shop_discounts', 'shop_discounts.id', '=', 'shop_item_discounts.shop_discount_id')
    ->where('shop_discounts.active', '=', 1)
    ->where('shop_discounts.start_datetime', '<', Core_Date::timestamp2sql(time()))
    ->where('shop_discounts.end_datetime', '>', Core_Date::timestamp2sql(time()))
    ->where('shop_discounts.deleted', '=', 0)
    ->where('shop_items.modification_id', '=', 0)
    ->clearOrderBy()
    ->orderBy('RAND()');

$Shop_Controller_Show->show();