magento 2 best seller product display based on current category and subcategories

Magento 2 getting best seller based on category wise displaying i have done below for that to implement this functionality it is working fine for me.

step 1 create block file in our module folder

<?php
namespace Pawan\Bestseller\Block;
use Magento\Catalog\Api\CategoryRepositoryInterface;
class Bestsellercategory extends \Magento\Catalog\Block\Product\ListProduct {

    /**
     * Product collection model
     *
     * @var Magento\Catalog\Model\Resource\Product\Collection
     */
    protected $_collection;

    /**
     * Product collection model
     *
     * @var Magento\Catalog\Model\Resource\Product\Collection
     */
    protected $_productCollection;

    /**
     * Image helper
     *
     * @var Magento\Catalog\Helper\Image
     */
    protected $_imageHelper;

    /**
     * Catalog Layer
     *
     * @var \Magento\Catalog\Model\Layer\Resolver
     */
    protected $_catalogLayer;

    /**
     * @var \Magento\Framework\Data\Helper\PostHelper
     */
    protected $_postDataHelper;

    /**
     * @var \Magento\Framework\Url\Helper\Data
     */
    protected $urlHelper;

    /**
     * @var \Magento\Catalog\Helper\Image
     */
    protected $imageHelper;

    /**
     * @var \Magento\Catalog\Helper\Image
     */
    protected $_scopeConfig;

    /**
     * @var \Magento\Catalog\Api\CategoryRepositoryInterface
     */
    protected $categoryRepository;

    protected $_registry;
    /**
     * Initialize
     *
     * @param \Magento\Catalog\Block\Product\Context $context
     * @param \Magento\Framework\Data\Helper\PostHelper $postDataHelper
     * @param \Magento\Catalog\Model\Layer\Resolver $layerResolver
     * @param \CategoryRepositoryInterface $categoryRepository
     * @param \Magento\Framework\Url\Helper\Data $urlHelper
     * @param \Magento\Catalog\Model\ResourceModel\Product\Collection $collection
     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
     * @param \Magento\Catalog\Helper\Image $imageHelper
     * @param array $data
     */
    public function __construct(
    \Magento\Catalog\Block\Product\Context $context, \Magento\Framework\Data\Helper\PostHelper $postDataHelper, \Magento\Catalog\Model\Layer\Resolver $layerResolver, CategoryRepositoryInterface $categoryRepository, \Magento\Catalog\Model\ResourceModel\Category\CollectionFactory $categoryCollection, \Magento\Framework\Url\Helper\Data $urlHelper, \Magento\Catalog\Model\ResourceModel\Product\Collection $collection, \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig, \Magento\Catalog\Helper\Image $imageHelper,\Magento\Framework\Registry $registry, array $data = []
    ) {
        $this->imageBuilder = $context->getImageBuilder();
        $this->_catalogLayer = $layerResolver->get();
        $this->_postDataHelper = $postDataHelper;
        $this->categoryRepository = $categoryRepository;
        $this->urlHelper = $urlHelper;
        $this->_collection = $collection;
        $this->_imageHelper = $imageHelper;
        $this->_scopeConfig = $scopeConfig;
        $this->_registry = $registry;
        parent::__construct($context, $postDataHelper, $layerResolver, $categoryRepository, $urlHelper, $data);
    }

    /**
     * Get product collection
     */
    protected function getProducts() {
        $limit = $this->getProductLimit();
        $sortby = 'rand()';
        $storeId = 0;
        $time = $this->getTimePeriod();

        $today = strtotime($this->_localeDate->date()->format('Y-m-d H:i:s'));
        $last = $today - (60 * 60 * 24 * $time);
        $from = date("Y-m-d H:i:s", $last);
        $to = date("Y-m-d H:i:s", $today);


        $fromDate = date("Y-m-d H:i:s", $last); //$this->getStartDate();
        $toDate = date("Y-m-d H:i:s", $today); //$this->getEndDate();
        
        $category = $this->_registry->registry('current_category');//get current category
//        $category->getId();
//        $writer = new \Zend\Log\Writer\Stream(BP . '/var/log/bestseller.log');
//        $logger = new \Zend\Log\Logger();
//        $logger->addWriter($writer);
       
        $categoryObj = $this->categoryRepository->get($category->getId());
        $subcategories = $categoryObj->getChildrenCategories();
        foreach($subcategories as $subcategorie) {
            $subcatids[] = $subcategorie->getId();
            $subcatnames[] = $subcategorie->getName();
            if($subcategorie->hasChildren()) {
                $childCategoryObj = $this->categoryRepository->get($subcategorie->getId());
                $childSubcategories = $childCategoryObj->getChildrenCategories();
                foreach($childSubcategories as $childSubcategorie) {
                   $subcatids[] = $childSubcategorie->getId();
                   $subcatnames[] = $childSubcategorie->getName();
                }
            }
        }
//        $logger->info($this->getProductLimit());
       
        
        $sqlQuery = "e.entity_id = aggregation.product_id";
        if ($storeId > 0) {
            $sqlQuery .=" AND aggregation.store_id={$storeId}";
        }
        if ($fromDate != '' && $toDate != '') {
            $sqlQuery .=" AND aggregation.period BETWEEN '{$fromDate}' AND '{$toDate}'";
        }
        $this->_collection->clear()->getSelect()->reset('where');
        $collection = $this->_collection
                ->addMinimalPrice()
                ->addFinalPrice()
                ->addTaxPercents()
                ->addAttributeToSelect('name')
                ->addAttributeToSelect('image')
                ->addAttributeToSelect('news_from_date')
                ->addAttributeToSelect('news_to_date')
                ->addAttributeToSelect('special_price')
                ->addAttributeToSelect('special_from_date')
                ->addAttributeToSelect('special_to_date')
                ->addAttributeToSelect('*');
//          ->addAttributeToFilter('is_saleable', 1, 'left')
//          ->addAttributeToFilter('status', 1)
//          ->addAttributeToFilter('visibility', 4);
        $collection->addCategoriesFilter(["in" => $subcatids]);
        if ($this->getSortbyCollection() == "product_name") {
            $sortby = "rand()";
        } else if ($this->getSortbyCollection() == "product_price") {
            $sortby = "price DESC";
        } else if ($this->getSortbyCollection() == "qty_ordered") {
            $sortby = "sold_quantity DESC";
        }
        $collection->getSelect()->joinRight(
                array('aggregation' => 'sales_bestsellers_aggregated_monthly'), $sqlQuery, array('SUM(aggregation.qty_ordered) AS sold_quantity')
        )->group('e.entity_id')->order($sortby)->limit($limit);
        $collection->getSelect();

        $this->_productCollection = $collection;
        return $this->_productCollection;
    }

    /*
     * Load and return product collection 
     */

    public function getLoadedProductCollection() {
        return $this->getProducts();
    }

    /*
     * Get product toolbar
     */

    public function getToolbarHtml() {
        return $this->getChildHtml('pager');
    }

    /*
     * Get grid mode
     */

    public function getMode() {
        return 'grid';
    }

    /**
     * Get image helper
     */
    public function getImageHelper() {
        return $this->_imageHelper;
    }
    public function getTimePeriod() {
        return $this->_scopeConfig->getValue('bestseller/setting/time', \Magento\Store\Model\ScopeInterface::SCOPE_STORE);
    }

    public function getProductLimit() {
        //return $this->_scopeConfig->getValue('bestsellerproducts_settings/vertical_setting/limit', \Magento\Store\Model\ScopeInterface::SCOPE_STORE);
        return $this->_scopeConfig->getValue('bestseller/setting/row', \Magento\Store\Model\ScopeInterface::SCOPE_STORE);
    }

    public function getVisibleStatus() {

        $visibleStatus = 4;
        return $visibleStatus;
    }

}
?>
step2 :: get products in your phtml file  by calling below format

<?php $_products = $block->getLoadedProductCollection(); ?>

<?php

echo "<pre />";

foreach ($_productCollection as $_product):

//    print_r($_product->getData());

   echo $_product->getName()."<br />";

endforeach;

?>