Smile\ElasticsuiteCatalog\Model\ResourceModel\Product\Indexer\Fulltext\Action\Full::addIsVisibleInStoreFilter PHP Method

addIsVisibleInStoreFilter() private method

Note : Magento put only enabled products that have the following visibility into the catalog_category_product_index table : - visible in catalog - visible in search - visible in catalog & search So joining on the root category will filter only products that have to be indexed and you don't need to put any additional filter on the visibility field.
private addIsVisibleInStoreFilter ( Zend_Db_Select $select, integer $storeId ) : Full
$select Zend_Db_Select Product select to be filtered.
$storeId integer Store Id
return Full Self Reference
    private function addIsVisibleInStoreFilter($select, $storeId)
    {
        $rootCategoryId = $this->getRootCategoryId($storeId);
        $indexTable = $this->getTable('catalog_category_product_index');
        $visibilityJoinCond = $this->getConnection()->quoteInto('visibility.product_id = e.entity_id AND visibility.store_id = ?', $storeId);
        $select->useStraightJoin(true)->join(['visibility' => $indexTable], $visibilityJoinCond, ['visibility'])->where('visibility.category_id = ?', (int) $rootCategoryId);
        return $this;
    }