See if this helps:
1. Create a parameter as shown below:
2. Write a filter condition as shown below:
3. Display the parameter for selection by user. And here is the output:
Hope this helps. Updated workbook is attached.
Example.twbx 2.5 MB
This solution is pretty close to what I was looking for!!
What if there are 5 different categories and user wants to select 2 out of 5 or 3 out of 5?
I knew you would come back with this. But, there were no exceptions stated. So, go ahead, give me or yourself credit for getting to the solution. Then, we can look at other solution(s) if possible.