Well this was an interesting challenge. I created a second sheet that builds out the Title and each selected comma delimited option split out into separate rows. This allowed me to create relation and lookup columns that link the title in the main sheet to the title in the crosswalk sheet. You can assign the Lookup column to the filter (I assigned Topics to the Filter). The formula in the sheet was copied from the web, so I haven’t taken the time to fully understand how it works, but it gave me what I was looking for. You can copy the app. I did scrub the names and email addresses.