[WordPress] Get posts by taxonomy of a post type.

gistfile1.php

<?php
// get post type
$post_type = get_post_type();
//$post_type = get_query_var('post_type'); // in post type archive

// get taxonomy objects of the post type
$post_type_taxonomies = get_object_taxonomies( $post_type, 'objects' );

if ( !empty($post_type_taxonomies) ) {
	foreach( $post_type_taxonomies as $post_type_taxonomy ) {
	
		// use only hierarchical taxonomy
		if ( is_object($post_type_taxonomy) && $post_type_taxonomy->hierarchical ) {
			
			// get terms by taxonomy name
			$terms = get_terms( $post_type_taxonomy->name );
			if ( ! is_wp_error( $terms ) ) {
				
				foreach ( $terms as $term ) {
					// get posts by each term
					$args = array(
						'post_type' => $post_type,
						'tax_query' => array(
							array(
								'taxonomy' => $term->taxonomy,
								'field' => 'slug',
								'terms' => $term->slug
							)
						)
					);
					$myposts = get_posts( $args );
					
					echo '<h3>' . $term->name . '</h3>';
					echo '<ul>';
					foreach( $myposts as $post ) {
						setup_postdata($post);
						echo '<li>' . get_the_title() . '</li>';
					}
					echo '</ul>';
					wp_reset_postdata();
				}
				
			}
			
		}
		
	}
}