Display posts of custom post type hierarchically by custom taxonomy

display-posts-of-custom-post-type-hierarchically-by-custom-taxonomy.php

add_filter('seopress_sitemaps_html_hierarchical_terms_query', 'sp_sitemaps_html_hierarchical_terms_query', 10, 2);
function sp_sitemaps_html_hierarchical_terms_query($cpt_key, $args_terms_query) {
    if ($cpt_key === 'testimonials') {//replace 'testimonials' with your own post type key
        $cats = get_terms('type', $args_terms_query);
        return $cats;
    }
    return;
}

add_filter('seopress_sitemaps_html_hierarchical_tax_query', 'sp_sitemaps_html_hierarchical_tax_query', 10, 3);
function sp_sitemaps_html_hierarchical_tax_query($cpt_key, $term, $args) {
    if ($cpt_key === 'testimonials') {//replace 'testimonials' with your own post type key
        unset($args['tax_query']);
        $args['tax_query'] = [[
            'taxonomy' => 'type', //replace 'type' with your own custom taxonomy key
            'field'    => 'term_id',
            'terms'    => $term->term_id,
        ]];
        return $args;
    }

    return;
}