function custom_bp_datebox($html, $type, $day, $month, $year, $field_id, $date) {       
    if($type == 'year'){
   
        $html = '<option value=""' . selected( $year, '', false ) . '>----</option>';

        for ( $i = 2015; $i > 2010; $i-- ) {
                $html .= '<option value="' . $i .'"' . selected( $year, $i, false ) . '>' . $i . '</option>';
        }
    }
    return $html;
}
add_filter( 'bp_get_the_profile_field_datebox', 'custom_bp_datebox',10,7);