protected function _initItems()
{
    parent::_initItems();
    foreach ($this->_items as $item) {
        $applyValue = $item->getLabel();
        if (($valuePos = array_search($applyValue, $this->currentFilterValue)) !== false) {
            $item->setIsSelected(true);
            $applyValue = $this->currentFilterValue;
            unset($applyValue[$valuePos]);
        } else {
            $applyValue = array_merge($this->currentFilterValue, [$applyValue]);
        }
        $item->setApplyFilterValue(array_values($applyValue));
    }
    return $this;
}

protected function _getItemsData()
{


    $attribute = $this->getAttributeModel();
    /** @var MagentoCatalogSearchModelResourceModelFulltextCollection $productCollection */
    $productCollection = $this->getLayer()->getProductCollection();

    $optionsFacetedData = $productCollection->getFacetedData($this->getFilterField());

    $items     = [];

    $attributeCode = $attribute->getAttributeCode();
    if ($attribute->getFrontendInput() == 'multiselect') {
      //echo '1<br/>';
        if($this->_coreRegistry->registry('current_category')) {
        //  echo '2<br/>';
            $catId = $this->_coreRegistry->registry('current_category')->getId();
            $facetSession = $this->_catalogSession->getData('multiselect_facets');
            if(isset($facetSession[$catId][$attributeCode]) && isset($_GET[$attributeCode])) {;
                $optionsFacetedData = $facetSession[$catId][$attributeCode];
            } else {
            //  echo '4<br/>';
                $optionsFacetedData = $productCollection->getFacetedData($this->getFilterField());
        // $optionsFacetedData returning all attributes after filter
                $facetArray = $facetSession;
                $facetArray[$catId][$attributeCode] = $optionsFacetedData;
                $this->_catalogSession->setData('multiselect_facets', $facetArray);
            }
        } else {
            $catId = 'search';
            $facetSession = $this->_catalogSession->getData('multiselect_facets');

            if(isset($facetSession[$catId][$attributeCode]) && isset($_GET[$attributeCode])) {

                $optionsFacetedData = $facetSession[$catId][$attributeCode];
            } else {
                $optionsFacetedData = $productCollection->getFacetedData($this->getFilterField());
                $facetArray = $facetSession;
                $facetArray[$catId][$attributeCode] = $optionsFacetedData;

                $this->_catalogSession->setData('multiselect_facets', $facetArray);
            }
        }
    }

    if (isset($optionsFacetedData['__other_docs'])) {
        $this->hasMoreItems = $optionsFacetedData['__other_docs']['count'] > 0;
        unset($optionsFacetedData['__other_docs']);
    }

    foreach ($optionsFacetedData as $value => $data) {
        $items[$value] = [
            'label' => $this->tagFilter->filter($value),
            'value' => $value,
            'count' => $data['count'],
        ];
    }

    $items = $this->addOptionsData($items);

    return $items;
}