private function getAjaxLoadUrl()
{
$qsParams = ['filterName' => $this->getFilter()->getRequestVar()];
$currentCategory = $this->getFilter()->getLayer()->getCurrentCategory();
if ($currentCategory && $currentCategory->getId() && $currentCategory->getLevel() > 1) {
$qsParams['cat'] = $currentCategory->getId();
}
$urlParams = ['_current' => true, '_query' => $qsParams];
return $this->_urlBuilder->getUrl('catalog/navigation_filter/ajax', $urlParams);
}