Count Selected vs count Total-Selected

Hi guys,

Is it doable in Tableau

I have a field Purpose of visit. I'd like use the quick filter of Purpose of visit for showing count for only 1 selected tag and counts of all others tags.

For example : Total counts 81 respondents. If I select tag "Specific topic", counts for it =20 and all others 61.

Others words: Show actual count for selected tag and all others =Total - selected tag.

I found a good example, but I do something wrong.

Could you help me?

Thanks,