Improved Nested Queries In Cdbcriteria

$criteria=new CDbCriteria;		
$criteria->addCondition("active_to >= :active_to and 
job_id in(select distinct job_id from job_req_trade where trade_id 
    in (select trade_id from user_trade where registration_id=:registration_id))  ");
$criteria->params = array('registration_id'=>$reg_id, 'active_to' => date('Y-m-d'));
$dataProvider = new CActiveDataProvider('Job', array(
	'criteria'=>$criteria,			
));

The above returns jobs matching a job seeker's trades skills. How can I improve the above condition in CDbCriteria. it has double "IN".

Thanks