<?php
                $thepostid = $post->ID;
                $product_object = $thepostid ? wc_get_product( $thepostid ) : new WC_Product();

                $product_ids = $product_object->get_upsell_ids( 'edit' );
                foreach ( $product_ids as $product_id ) {
                    $product = wc_get_product( $product_id );
                    if ( is_object( $product ) ) {
                        echo get_the_title($product_id);
                    }
                }

                ?>