Hi @samg,
it refers to cascading, something you will need if you want to apply specific filters.
This could be something working for you.
Other than that have a look at that tutorial: https://www.youtube.com/watch?v=4YdHRswXQu8
Specifically around 12:15 and see if that's something you would look for.
Directly creating a search from a multi choice field will not work easily.
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Hope that helps.
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