Here is the code i am using for "select_advance" field
array(
'id' => $prefix.'role',
'name' => __( 'Select User Role:', 'meta-box' ),
'type' => 'select_advanced',
//'required' => true,
'multiple' => true,
'options' => $user_roles,
),
,
Cloning of "select_advance" working fine if "mutiple" option is false, so its only happeining with multiple select option enable.
