Hi! I came across the same challenge. I managed to solve this with a simple onLoad client script on the associated record producer, that fetches the template sys_id from the URL opened (assuming you create Cat Item from Template), when you open a new cat item from a template. What did not work for me though, is when you did not have the variable loaded into any of the sections, so I did the following.
1. Implement the client script that fetches the sys_id of the template and load it into a variable you have on the associated producer (assuming your variable field is called template_id)
function onLoad() {
var url = this.location.href;
var templateIdMatch = url.match(/template-id\/([a-zA-Z0-9]+)\b/);
if (templateIdMatch && templateIdMatch[1]) {
g_form.setValue('template_id', templateIdMatch[1]);
g_form.setReadOnly('template_id', true);
g_form.setVisible('template_id', false); // You can also have another UI policy to hide this field completely on load. (Step 2 or 3 in this post)
}
2. Put the template_id field into any of the sections, and hide it by an onLoad UI Policy. At best, you can create a new section to which you only map this variable, so you can hide it easily (e.g. template_id is not empty - as you have loaded the value by the client script)
3. Create another UI Policy that shows or hides your required variables in any other section on the Catalog Builder. Best to keep them in one Section, so if you set all of them visible = false the complete section and step will not show up. For safety I would also set then those fields in this section non mandatory, and read only.
Let me know by marking accept as solution if this worked for me. If you need any other details, feel free to message me.
