Thanks @mwiktowy for doing something I have being intending to for some time, the result is somewhat simple compared to what I imagined. From here we can;
- Add a tag to introduce new elements to the filter pill as with tag pills $:/tags/TagDropdown
- Create an alternative tag pill that looks like the regular ones but that responds to a filter eg todo not done
- Make pills look a little different from tag pills
- Perhaps add icons
- Field value pill with drag and drop reordering
Thanks for the inspiration at the beginning of my Wednesday.