.
.
specify the directory -
$assets = dirname(__FILE__).'/assets';
$baseUrl = Yii::app()->assetManager->publish($assets);
this way to include external css and js files to your view page -
Yii::app()->clientScript->registerCssFile($baseUrl . '/css/style.css');
Yii::app()->clientScript->registerScriptFile($baseUrl . '/js/jquery.js');