They are not displayed anywhere. They are not displayed in the settings, nor are they displayed in the "Fields and View shortcode" lookup.
This may not be a bug, and a fact that you simply have to remember the shortcodes you add yourself, but it would be nice if I could see the registered shortcodes somewhere along with the rest of the view shortcodes or at least show the shortcodes in the settings, so when I come back to my work after a few weeks, I can look the names of the shortcode up, instead of reading my plugin code 🙂
Am I doing something wrong or do third party shortcodes simply not show up anywhere in the toolset tools.
Right now third party shortcodes are not shown anywhere. You have to know they exists.
But since they are added either through setup or through the filter, it should be possible to display these shortcodes somewhere in the visual wizard, or in the settings.
I can't remember what I did 2 weeks ago, so it would be nice to be able to see the registered shortcodes that work with toolset. That way when you have to alter a content template or some other designs, you kan see your registered shortcodes somewhere.
Most of the time these shortcodes are shortcodes you have to build yourself, in order to get a view or content template to do what you need it to do. So it would be nice to be able to see the registered third party shortcodes in the visual wizard or somewhere else.
I think this would be a good idea but it is up to the dev's discretion to add this. The reason is that it is up to the 3rd party shortcode makers to provide an interface to add their shortcodes.
But I do get the point that you are making and i'll add this to the list of feature request for views.