I want to create a script tool in a regular ArcMap toolbox (not python tool box if possible) and have a multi-value field input parameter that allows you to sort the input fields, just like the "Attributes of Interest" input in the "Similarity Search" GP Tool in the built-in Spatial Stats Tools toolbox. I can get a regular multi-value field input, but that only gives me all of the fields (that meet the filter requirements) in a pre-populated list, with check-boxes. What my script tool needs however, is to get a list of field names from the user in a user specified order.
The "Similarity Search" GP tool has 2 inputs at the end of that tool that do exactly what I am wanting, and I've compared their settings with mine and I see nothing different, but they have a sortable multi-field input. Additionally, if I copy that script tool into my own toolbox and delete the entire validation code section (code on the Validation tab of the script tool properties dialog), when I re-open that tool it still has the sortable multi-field input desired, so it does not appear to be validation code specific. However, if I change any of the parameter display names in that script tool's properties, it suddenly reverts to the regular multi-field select box.
How can I get my script tool to replicate the Similarity Search GP tool's multi-field input?
I'd ideally like: