Hi zwaters! Sorry for the delay. You are using table calculations (periodOverPeriod, etc), which as you correctly pointed out require the prior period data to be part of the query/visual (which is why you cant filter it out). This approach might not work for you table where you show each month, but if you just want a KPI that compares the last 12 months to the 12 months before that I would do it like we explain in this article: Period Over Period and Other Date Comparison Calculations (YoY, MoM, YTD, Rolling 7 days, etc)
So yours would look like:
Last 12 months: ifelse(dateDiff({order_date},now(),"MM") <= 12, sales, 0)
Last 13-24 months: ifelse(dateDiff({order_date},now(),"MM") <= 24 AND dateDiff({order_date},now(),"MM") >12, sales, 0)
YoY %: sum(Last 12 Months) / sum(Last 13-24 months) - 1
Then just put that last YoY % into your KPI visual (no filters needed).
Also now() is measuring it relative to the current date. You can change that to a parameter, or you could make another calc that finds the latest date in your data set and use that in here instead (would look like maxOver({your date field}, [ ], PRE_FILTER)