Filter Drop down

You can create a custom IDA call through the API designer. You can specify which key number you would like to use (in this case will be the field that you are already selecting) and option search criteria (the parent field you want to filter by).

Another way to do it would be to add or modify the screen rules for this specific form, but that would mean maintaining it going forward.

Hope this helps.

If you dont' want to change the functionality of the delivered screen then you will need to develpp a custom dropdown with Design Studio using javascript in the Script area instead of dragging a dropdown list and attaching a data element to it.

Thanks to you both for taking the time to reply. Is there a kb article or document about how to format the xml line creating the box and calling the filtered data?