Код такой
public function list_products_html( $lang = false ) {
            ob_start();
            /**
             * WPML Suppot:  Localize Ajax Call
             */
            global $sitepress;
            if( defined( 'ICL_LANGUAGE_CODE' ) && $lang && isset( $sitepress )) {
                $sitepress->switch_lang( $lang, true );
            }
            if ( empty( $this->products_list ) ) {
                echo '' . __( 'No products to compare', 'yith-woocommerce-compare' ) . '';
                return ob_get_clean();
            }
            $count = 0;
            foreach ( $this->products_list as $product_id ) {
                /**
                 * @type object $product /WC_Product
                 */
                $product = $this->wc_get_product( $product_id );
                    $count++;
                ?>
            <?php
            }
             echo $count;
            $return = ob_get_clean();
            return apply_filters( 'yith_woocompare_widget_products_html', $return, $this->products_list, $this );
        }
и в шаблоне
<?php global $yith_woocompare;
     echo $yith_woocompare->obj->list_products_html();   
?>