Add groupbuy counter in the loop WC 3.0 +

        add_action( 'woocommerce_after_shop_loop_item_title','wpgenie_show_counter_in_loop',50 );

        function wpgenie_show_counter_in_loop(){

            global $product;

            $time = '';

            if(!isset ($product))
                return;
            if('groupbuy' != $product->get_type())
                return;

            $timetext = __('Time left', 'wc_groupbuy');

            if(!$product->is_started()){
                $timetext = __('Starting in', 'wc_groupbuy');
                $counter_time = $product->get_seconds_to_groupbuy();
            } else{
                $counter_time = $product->get_seconds_remaining();
            }

            $time = '<span class="time-left">'.$timetext.'</span>
            <div class="groupbuy-time-countdown"
            data-time="'.$counter_time.'"
            data-groupbuyid="'.$product->get_id().'" data-format="'.get_option(
            'simple_groupbuy_countdown_format' ).'"></div>';

            if($product->is_closed()){
                $time = '<span class="has-finished">'.__('Group Buy deal finished','wc_groupbuy').'</span>';
            }
            echo $time;
        }