I know I'm necro-posting but I recently had the same issue. Please note that I used Rao's solution on SO to get to this answer.
Assuming your CPT is called "notes".
/**
* @see https://codex.wordpress.org/Plugin_API/Filter_Reference/menu_order
*/
add_filter( 'custom_menu_order', 'change_note_submenu_order' );
/**
* Change the submenu order for the Note CPT in the Admin panel
*
* @param [type] $menu_ord I don't think this is actually used for anything...
* @return [type] $menu_ord
* @see https://stackoverflow.com/questions/18766477/wordpress-change-admin-submenu-order
*/
function change_note_submenu_order( $menu_ord ) {
global $submenu;
/* Uncomment the line below to see all menu orders */
// echo '<pre>'.print_r($submenu,true).'</pre>';
/**
* NOTE: Original note submenu order should be:
* 5 (note list),
* 10 (Add new),
* 15 (Categories),
* 16 (Tags),
* 17 (Your Custom Page added via add_submenu_page) */
$arr = array();
$arr[] = $submenu['edit.php?post_type=note'][17]; // Custom menu page (Omit if unused)
$arr[] = $submenu['edit.php?post_type=note'][5]; // Note List
$arr[] = $submenu['edit.php?post_type=note'][10]; // Add New Note
$arr[] = $submenu['edit.php?post_type=note'][15]; // Categories
$arr[] = $submenu['edit.php?post_type=note'][16]; // Tags
$submenu['edit.php?post_type=note'] = $arr;
return $menu_ord;
}
Definitely comment out the echo '<pre>'.print_r($submenu,true).'</pre>';
if your having trouble. Also remember you can manually set the array too in the change_note_submenu_order
function.
$notes_list = array("Notes", "edit_posts", "edit.php?post_type=notes");
$custom_page = array("Custom Menu Page Title", "Capability", "Menu Slug", "Page Title");
$new_note = array("Add New", "edit_posts", "post-new.php?post_type=note");
$arr = array($custom_page, $notes_list, $new_note);
$submenu['edit.php?post_type=note'] = $arr;
Hope this helps somebody!