Thank you for your message.
I have put a video in the private content area, as well as the source code.
Please note, this is currently only on a local dev environment.
We copied the ‘et-core-plugin/app/models/widgets/brands-filter.php’ to create the widget.
We replaced all brand references with our diet taxonomy.
As you can see on the video the behaviour is a little bit different to the one of the brand selection. When a brand is selected, the page is not actively refreshed, instead the JS loader popups and refreshes the content.
However, on the diet filter the page gets actually refreshed and as it seems the products are not filtered by the filter.