function get_term_top_most_parent($term_id, $taxonomy){
    $parent = get_term_by( 'id', $term_id, $taxonomy);
    while ($parent->parent != 0){
        $parent = get_term_by( 'id', $term_id, $taxonomy);
    }
    return $parent;
}
// so once you have this function you can just loop over the results returned by wp_get_object_terms
 
function hey_top_parents($taxonomy) {
		global $post;
        $terms = wp_get_object_terms(post->ID, $taxonomy);
        $top_parent_terms = array();
        foreach ($terms as $term){
                //get top level parent
                $top_parent = get_term_top_most_parent($term->ID, $taxonomy);
                //check if you have it in your array to only add it once
                if (!in_array($top_parent->ID,$top_parent_terms)){
                        $top_parent_terms[] = $top_parent;
                }
        }
        foreach ($top_parent_terms as $term) {
			$r = '<a href="' . get_term_link($term->slug, $taxonomy) . '">' . $term->name . '</a>';
               
        }
       
        // return $r;
       
        return print_r($top_parent_terms);
        // This shows an empty array (( [0] => )), so could  the problem be with the get_term_top_most_parent() function?
 
} // End of top parents