Woocommerce search form with category select

You can try below code. Below code shows search box and woocommerce product categories . It will also show selected category.

   <form name="myform" method="GET" action="<?php echo esc_url(home_url("https://wordpress.stackexchange.com/")); ?>">

    <?php if (class_exists('WooCommerce')) : ?>
  <?php 
  if(isset($_REQUEST['product_cat']) && !empty($_REQUEST['product_cat']))
  {
   $optsetlect=$_REQUEST['product_cat'];
  }
 else{
  $optsetlect=0;  
  }
         $args = array(
                    'show_option_all' => esc_html__( 'All Categories', 'woocommerce' ),
                    'hierarchical' => 1,
                    'class' => 'cat',
                    'echo' => 1,
                    'value_field' => 'slug',
                    'selected' => $optsetlect
                );
          $args['taxonomy'] = 'product_cat';
          $args['name'] = 'product_cat';              
          $args['class'] = 'cate-dropdown hidden-xs';
          wp_dropdown_categories($args);

   ?>
  <input type="hidden" value="product" name="post_type">
<?php endif; ?>
               <input type="text"  name="s" class="searchbox" maxlength="128" value="<?php echo get_search_query(); ?>" placeholder="<?php esc_attr_e('Search entire store here...', 'woocommerce'); ?>">

    <button type="submit" title="<?php esc_attr_e('Search', 'woocommerce'); ?>" class="search-btn-bg"><span><?php esc_attr_e('Search','woocommerce');?></span></button>
  </form>