I have a subject tree in the customer-service application. And we use that on the Create Case form on self-service portal.
We have a first field "Subject" and second one "Sub-subjects", on the portal they both display the same content.
The need is to select first the sub-subject, and should automatically get the parent (the subject)
Thanks you very much!
Found a solution:
I followed this tuto: Custom lookup filtering
To resume, I created a web template that will retrieve my Subjects, then I used the $getJSON to read the web template result.