Hide option values in a multi select question based on the URL

[DarrylKlassen1]

I am creating a Dashboard to track users watching safety videos.  When a user selects a "season" and a piece of "equipment" they are presented with a multi - select that allows them to click which videos on that specific piece of equipment they have watched.  Then they submit the survey.  

Subsequently, in my Dashboard, i am showing this information, but would like to provide them with a link to the survey - with most of the data already filled in.  I have accomplished this using URL parameters, but what I cannot figure out is, if they watched video 1 and video 2 on a certain piece of equipment, how to eliminate those choices on this newly linked URL?  So they can only select videos they have not already watched and acknowledged.

As you can see from above in my Dashbord Table - i have a URL created using this syntax:

?field:username=" + f['username'] + "&field:season=" + f['season'] + "&field:equipment=" + f['equipment']

but is it possible to have the Video 1 and Video 2 eliminated from my form as choices when it opens?

Thanks

[DarrylKlassen1]

Thanks @abureaux , i have this working using this in my choice_filter:

selected(${hide_multiselect},label)

But this is achieving the opposite of what I want - is there a NOT selected option?  so the multi-choice shows the options that are not in my list?

Thanks

[abureaux]

Excellent news! Okay, as I mentioned below, I realized after the fact that what I provided is technically the reverse of what you are looking for. But, now that you have it working like this, it is just a matter of "reversing" the process. Give this a try: