Filter relate field pop up

I am using suitecrm 8.6 and have 3 modules
Industry
Sub Industry
Account
In accounts i want to select record from industry and filter sub industries according to selected industry
i tried this but it didn’t work

 0 =>
          array (
            'name' => 'sub_industry_c',
            'studio' => 'visible',
            'label' => 'LBL_SUB_INDUSTRY',
              'displayParams' =>
            array (
              'initial_filter' => '&industry="+this.form.{$fields.industry2_c.name}.value+"',
            ),
          ),

Thanks in advance

Try this structure in your code:

'displayParams' => array(
    'initial_filter' => '&industry_advanced=" + document.getElementsByName(\'industry2_c\')[0].value + "',
),

It is a missing feature in 8.x