Thanks! That works. Here is what i have
ifelse(
${Period} = 'Weekly', periodOverPeriodDifference(avg(rating),Period, WEEK, 1),
${Period} = 'Monthly', periodOverPeriodDifference(avg(rating),Period, MONTH, 1),
periodOverPeriodDifference(avg(rating),Period, YEAR, 1)
) * distinct_count({feedback_id})
I was following this post to use the parameter…I think it works there but not in my case