Hi observableTalk,
Is it possible to use the dropdown menu as a parameter embedded in the url when we generate the iframe?
I am asking this because we want to embed the visualization in an app, but depending on the page we want to be able to select a specific option in the dropdown menu.
see example here
However, when I generate the iframe I can’t see any parameter in the url that would modify the option in the dropdown menu.
Hope the question is clear, thanks in advance 
You could parameterize the notebook with a query parameter and then include the query parameter as the value of your drop down menu. Here’s a fork of your notebook that does so:
And here’s a link to an embedded version. Note, though, that I did need to add the extra query parameter to the URL manually to get this to work. That might be a little oversight in the automatic embedding code.
Mark this is exactly what I was looking for, and it is a really simple solution.
Thanks a lot