add_action( 'cmb2_admin_init', 'cs_register_demo_metabox' );
function cs_register_demo_metabox() {

	$cmb = new_cmb2_box( array(
		'id'           => 'box_id',
                'title'        => 'Title',
	) );

	$cmb->add_field( array(
		'id' => 'orderby_param',
		'name' => 'Orderby parameters', 
		'desc' => 'Sort retrieved posts by parameter. Defaults to "date". ',
		'type' => 'select',
		'default' => 'date',
		'options' => array(
				'none' => 'No order',
				'ID' => 'Order by post id',
				'author' => 'Order by author',
				'name' => 'Order by title',
				'name' => 'Order by post name (post slug)',
				'date' => 'Order by date',
				'modified' => 'Order by last modified date',
				'parent' => 'Order by post/page parent id',
				'rand' => 'Random order',
				'comment_count' => 'Order by number of comments',
				'menu_order' => 'Order by Page Order',
				'meta_value' => 'Order by string meta value',
				'meta_value_num' => 'Order by numeric meta value ',
				'post__in' => 'Preserve post ID order given in the post__in array',
		)
	) );
	
}