Pagination deep relational sorting

gistfile1.php

# Controller -
<?php
$this->paginate = array(
	'limit' => 50,
	'contain' => array(
		'ExceptionWorkflowLog',
		'Procedure(id,cpt,expected_amount,allowed_total,difference_amount)',
		'Procedure.Claim(id,number)',
		'Procedure.Claim.Group(abbr)',
		'Procedure.Payer(abbr)'
	)
);
		
$this->set('exceptions', $this->paginate('PaymentException'));
?>

# View - 
<?php echo $this->Paginator->sort('Payer', 'Procedure.Payer.abbr'); ?>

# Relationships - 
PaymentException belongsTo Procedure
Procedure belongsTo Payer