add_action( 'restrict_manage_posts', 'my_restrict_manage_posts' );
function my_restrict_manage_posts() {
// only display these taxonomy filters on desired custom post_type listings
global $typenow;
if ($typenow == 'photos' || $typenow == 'videos') {
// create an array of taxonomy slugs you want to filter by - if you want to retrieve all taxonomies, could use get_taxonomies() to build the list
$filters = array('plants', 'animals', 'insects');
foreach ($filters as $tax_slug) {
// retrieve the taxonomy object
$tax_obj = get_taxonomy($tax_slug);
$tax_name = $tax_obj->labels->name;
// retrieve array of term objects per taxonomy
$terms = get_terms($tax_slug);
// output html for taxonomy dropdown filter
echo "<select name='$tax_slug' id='$tax_slug' class='postform'>";
echo "<option value=''>Show All $tax_name</option>";
foreach ($terms as $term) {
// output each select option line, check against the last $_GET to show the current option selected
echo '<option value='. $term->slug, $_GET[$tax_slug] == $term->slug ? ' selected="selected"' : '','>' . $term->name .' (' . $term->count .')</option>';
}
echo "</select>";
}
}
}