Hide some Filter options (SAC)

Hallo Everyone,

I have the following question: I have a Filter called "Region", but i want to hide some options, so the user cant select them.

For example my regions are: "Berlin", "Hamburg" and "Cologne". But I want to select the option "Berlin" fixed, so that the user can only select "Hamburg" and "Cologne". The option "Berlin" should always be selected, but I dont want it to be seen in the filter.

Does one of you have an idea?

Thank you.