Hide fields on multiple parent pages & hiding groups

I'm trying to hide a field on multiple parent pages, I can't get it to work like this:

'hidden' => array('parent_id', array(31,35,37)),

Is there a way to make this work?

I'm also trying to hide groups, but can't seem to make it work, like this:

array(
	'id'     => 'buttons_group',
	'name'   => __( 'Buttons', 'rolling' ),
	'type'   => 'group', 
	'clone'  => true,    
	'sort_clone' => true,
	'hidden' => array('parent_id', 31),
	'fields' => array(

This will not hide the group, I can hide individual fields in the group, but the group and clone button always remain.

Thanks!