initial filter in relate field with coding

Hi,
i have created relate field with the coding how can i use initial filter into that.
step :1

step 2:
$popup_tutor_data = array(
‘call_back_function’ => ‘set_return’,
‘form_name’ => ‘EditView’,
‘field_to_name_array’ => array(
‘id’ => ‘exclude_tutor_c’,
‘user_name_c’ => ‘tutor_name_exclude’,
),
);
$this->ss->assign(‘encoded_tutors_popup_request_data’, $json->encode($popup_tutor_data));

how can i add initial filter to this code