Solution - 1

Hello, I think I've cracked that. It's possible to query by custom taxonomies - it's just has not been documented yet. OK, I hope I've understood the question right. Here we go. I've used the default TwentyTen theme with a custom taxonomy called "Catalog" and post type called "Products". 1) Put this in functions.php

// register custom post types and taxonomies
function register_custom_post_types() {
	
	// register custom post type
	$labels = array(
		'name' => 'Products',
		'singular_name' => 'Product'
	);
	
	$args = array(
		'labels' => $labels,
		'public' => true,
		'capability_type' => 'post',
	); 
	
	register_post_type('products', $args);
	
	// register taxonomy
	$labels = array(
		'name' => 'Catalogs',
		'singular_name' => 'Catalog',
	); 	

	register_taxonomy('catalog', array('products'), array(
		'hierarchical' => true,
		'labels' => $labels,
		'public' => true
		)
	);
	
}
add_action('init', 'register_custom_post_types');

<?php
// taxonomy-catalog.php

// set variables
$term = get_term_by( 'slug', get_query_var( 'term' ), get_query_var( 'taxonomy' ) );
$tax = get_query_var( 'taxonomy' );
 
get_header(); ?>

		<div id="container">
			<div id="content" role="main">

				<h1 class="page-title"><?php echo $term->name; ?></h1>
				<?php
				
				// if term has children
				if (get_term_children($term->term_id, $tax) != null) {

					// get child terms
					$term_children = get_terms(
						$tax, 
						array(
							'child_of' => $term->term_id,
						)
					);
					
					// loop through them
					foreach ($term_children as $term_child) {
					
						// print title
						echo '<h2>' . $term_child->name . '</h2>';
					
						// change query
						query_posts(array(
							'catalog' => $term_child->slug,
							)
						);
						
						// loop through posts
						if (have_posts()) : ?>
						
							<ul>
							
							<?php while (have_posts()) : the_post(); ?>
								
								<li <?php post_class(); ?>>
								
									<a rel="nofollow" href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
										
								</li>
								
							<?php endwhile; ?>
							
							</ul>
							
						<?php endif;
						
					}
					
				// if term has no chilren
				} else {
			
					// loop through posts
					if (have_posts()) : ?>
					
						<ul>
						
						<?php while (have_posts()) : the_post(); ?>
							
							<li <?php post_class(); ?>>
							
								<a rel="nofollow" href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
									
							</li>
							
						<?php endwhile; ?>
						
						</ul>
						
					<?php endif;
			
				}
				
				?>

			</div><!-- #content -->
		</div><!-- #container -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>

Solution - 2

Hi, You can further classified them using templates according to WordPress template hierarchy.

taxonomy-{taxonomy}-{term}.php - If the taxonomy were sometax, and taxonomy's slug were someterm WordPress would look for taxonomy-sometax-someterm.php taxonomy-{taxonomy}.php - If the taxonomy were sometax, WordPress would look for taxonomy-sometax.php

Solution - 3

I think you are in the situation to query posts by custom taxonomy... and that's not in WordPress, yet. You can do it with a custom select query. Something like this:

 $querystr = "
SELECT * 
FROM $wpdb->posts
LEFT JOIN $wpdb->term_relationships ON($wpdb->posts.ID = $wpdb->term_relationships.object_id)
LEFT JOIN $wpdb->term_taxonomy ON($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)
LEFT JOIN $wpdb->terms ON($wpdb->term_taxonomy.term_id = $wpdb->terms.term_id)
WHERE $wpdb->posts.post_type = 'post' 
AND $wpdb->posts.post_status = 'publish'
AND $wpdb->term_taxonomy.taxonomy = 'pants'
AND $wpdb->terms.slug = 'loose-fit' OR $wpdb->terms.slug = 'baggy-style'
ORDER BY $wpdb->posts.post_date DESC
";

 $pageposts = $wpdb->get_results($querystr, OBJECT);

Solution - 4

Its simple. even you can use your category.php file for your purpose. you just need to do setting in admin. it will display product only for selected category or subcategory whatever. Even you can also change the URL structure to your category and sub category name