Filter link expression based on value in ticket

Hi all,

In my ESS, I will select Service Recipient ( - the link will return ( and its department (

In ESS, I also have custom Requestor HOD Fill/Form field (requestor.hod) and corresponding custom link. The link will return (requestor.hod.dept) and (requestor.hod.approver). The requestor.hod.approver field is a checkbox, its ticked to indicate its an approver for that department.

I want to filter in the link where click on Requestor HOD field, return result if:

- requestor.hod.dept is same as AND and the requestor.hod.approver = true

Appreciate help on the expression syntax

Thanks in advanced.