How to get dependendent drop value in advanced search page

I hope someone can help me out here.

I have been trying to fetched dependent drop down values in cases advanced search.
there are two types of the drop down Type and Sub-Type, On advanced search page when user select the Type drop down then based on selected Type, Sub-type options should be populate.
I have implemented custom function to get sub-types in “Extension\application\Ext\Utils\function.php”

and in searchdefs.php called “getSubTypes” function.

[left]‘type’ =>
array (
‘type’ => ‘enum’,
‘default’ => true,
‘studio’ => ‘visible’,
‘label’ => ‘LBL_TYPE’,
‘width’ => ‘10%’,
‘name’ => ‘type’,
‘displayParams’ => array(
‘size’ => 1,
),
),
‘sub_type’ =>
array (
‘type’ => ‘dynamicenum’,
‘default’ => true,
‘studio’ => ‘visible’,
‘label’ => ‘LBL_SUB_TYPE’,
‘width’ => ‘10%’,
‘name’ => ‘sub_type’,
‘displayParams’ => array(
‘size’ => 1,
),
‘function’ =>
array (
‘name’ => ‘getSubTypes’,
‘params’ =>
array (
0 => false,
),
),
),
[/left]

But How to send Type drop down selected value to custom function?
there is another option in Studio to manage dynamic drop down, but it will only work for edit view and list view.
is there any way to set dynamic dependent drop down in advanced search?