I think this is what you are asking for, I made a pull request to include it in the core, but it isn't part of it yet. And the select widget has some problems so it may not be included until they are fixed. But if you want to try using it
here is a demo site.
The restriction is that you can't create the options with a list and have them trigger action widgets. There may be other problems but that is the only one I have found so far.