How to sell Fragment sets using public stash tabs.

I am trying to figure out how to list fragment sets for sale via a public stash tab. I have been able to set up buying a fragment set via a public stash tab, but cannot figure out how to sell fragment sets as there are four separate pieces.

I'm pretty sure this functionality doesn't exist any more unfortunately.

Does not work anymore.
If you are searching for sets on the trade website, it will find no results. So none is able to list ;)