Filtering post or custom post type by a specific taxonomy term in the WordPress admin

This is a powerful little snippet to allow filtering your post or custom post type by a specific taxonomy term in the WordPress admin.

In my use case I had a custom post type for ‘Team’ members. I then had a custom taxonomy called ‘Group’ that associated each member with one or more groups within the organization. The client wanted to be able to filter all Team members by Group in the admin.

My first thought was to use sortable columns, but that would still require scrolling and possibly paging to get the right people.

I tried a few things and ended up with this nice snippet…

The only thing you need to change is your post type and your taxonomy name. The rest is pretty much magic.

<?php
/**
 * Display a custom taxonomy dropdown in admin
 * @author Mike Hemberger
 * @link http://thestizmedia.com/custom-post-type-filter-admin-custom-taxonomy/
 */
add_action('restrict_manage_posts', 'tsm_filter_post_type_by_taxonomy');
function tsm_filter_post_type_by_taxonomy() {
	global $typenow;
	$post_type = 'team'; // change to your post type
	$taxonomy  = 'group'; // change to your taxonomy
	if ($typenow == $post_type) {
		$selected      = isset($_GET[$taxonomy]) ? $_GET[$taxonomy] : '';
		$info_taxonomy = get_taxonomy($taxonomy);
		wp_dropdown_categories(array(
			'show_option_all' => sprintf( __( 'Show all %s', 'textdomain' ), $info_taxonomy->label ),
			'taxonomy'        => $taxonomy,
			'name'            => $taxonomy,
			'orderby'         => 'name',
			'selected'        => $selected,
			'show_count'      => true,
			'hide_empty'      => true,
		));
	};
}
/**
 * Filter posts by taxonomy in admin
 * @author  Mike Hemberger
 * @link http://thestizmedia.com/custom-post-type-filter-admin-custom-taxonomy/
 */
add_filter('parse_query', 'tsm_convert_id_to_term_in_query');
function tsm_convert_id_to_term_in_query($query) {
	global $pagenow;
	$post_type = 'team'; // change to your post type
	$taxonomy  = 'group'; // change to your taxonomy
	$q_vars    = &$query->query_vars;
	if ( $pagenow == 'edit.php' && isset($q_vars['post_type']) && $q_vars['post_type'] == $post_type && isset($q_vars[$taxonomy]) && is_numeric($q_vars[$taxonomy]) && $q_vars[$taxonomy] != 0 ) {
		$term = get_term_by('id', $q_vars[$taxonomy], $taxonomy);
		$q_vars[$taxonomy] = $term->slug;
	}
}

https://thestizmedia.com/custom-post-type-filter-admin-custom-taxonomy/