This is an interesting problem. I know that we won't be able to achieve this using action filters on the field itself, because tableau is going to use OR logic instead of AND logic to apply the action filters. To my knowledge, there isn't a way to change that.
This means any solution to achieve this type of thing will probably require some calculations.
Assuming this is a dummy data set, how many keywords might be expected in a real data set like this?
In the real data set it could be 10 or even more and the keywords could be changing from time to time