Я так понял врачи - это должны быть custom post type. Направления - таксономии.
Что то типа такого:
add_action('init', 'my_add_posts_types');
function my_add_posts_types(){
register_taxonomy('department', array('doctors'), array(
'label' => __('Department','my'),
'labels' => array(
'name' => __('Department','my'),
'singular_name' => __('Department','my'),
'search_items' => __('Search Department','my'),
'all_items' => __('All Departments','my'),
'parent_item' => __('Department','my'),
'parent_item_colon' => __('Department','my'),
'edit_item' => __('Edit Department','my'),
'update_item' => __('Department','my'),
'add_new_item' => __('Add Department','my'),
'new_item_name' => __('add Department','my'),
'menu_name' => __('Department','my'),
),
'description' => __('Department description','my'),
'public' => true,
'show_in_nav_menus' => false,
'show_ui' => true,
'show_tagcloud' => false,
'hierarchical' => true,
'rewrite' => array('slug'=>'department', 'hierarchical'=>false, 'with_front'=>false, 'feed'=>false ),
'show_admin_column' => true,
) );
register_post_type('doctors', array(
'labels' => array(
'name' => __('Doctors','my'),
'singular_name' => __('Doctor','my'),
'add_new' => __('Add doctor','my'),
'add_new_item' => __('Add doctor','my'),
'edit_item' => __('Edit doctor','my'),
'new_item' => __('New doctor','my'),
'view_item' => __('See doctor','my'),
'search_items' => __('Search doctor','my'),
'not_found' => __('Not found doctors','my'),
'not_found_in_trash' => __('Not found doctors','my'),
'parent_item_colon' => '',
'menu_name' => __('Doctors','my'),
),
'public' => true,
'publicly_queryable' => true,
'show_ui' => true,
'show_in_menu' => true,
'query_var' => true,
'rewrite' => true,
'capability_type' => 'post',
'has_archive' => true,
'hierarchical' => false,
'menu_position' => null,
'supports' => array('title','editor','author','thumbnail','excerpt','comments')
) );
}