<form>
<select onchange="window.open(this.options[this.selectedIndex].value,'_top')">
<option value="">Select by Author</option>
<?php //Code to get a list of all authors with posts in this category, and then create a dropdown list of their names with links to their page
$category = get_queried_object();
$taxonomy_name = 'custom_taxonomy_name_here'; //Change to reflect the name of your custom taxonomy
$current_category = $category->slug;
echo '<h1>' . $current_category . 'testing</h1>';
$author_array = array();
$args = array(
'posts_per_page' => -1,
'post_type' => 'custom_post_type_here', //Change to your custom post type
'tax_query' => array(
array(
'taxonomy' => 'custom_taxonomy_name_here', //Change to reflect the name of your custom taxonomy
'field' => 'slug',
'terms' => $current_category
),
),
'orderby' => 'author',
'order' => 'ASC'
);
$cat_posts = get_posts($args);
foreach ($cat_posts as $cat_post) :
if (!in_array($cat_post->post_author,$author_array)) {
$author_array[] = $cat_post->post_author;
}
endforeach;
foreach ($author_array as $author) :
$auth = get_userdata($author)->display_name;
$nicename = get_userdata($author)->user_nicename;
echo '<option value="' . get_term_link( $category->slug, $taxonomy_name ) . '/' . $nicename . '">' . $auth . '</option>'; //creates the URL to our term, filtered by author
endforeach;
?>
</select>
</form>