I have attached a sample workbook where I am filtering for 3 months worth of data. The mean is calculated using WINDOW_AVG.
I am now wondering if it is possible to show the 3 months data but, on the same chart, show the average for the past 6 months.
I've managed to figure it out using this technique -
I filtered for the last 6 months and then filtered on a calculated field (IF INDEX() > 12 THEN 1 ELSE 0 END) which takes out the first 3 months of data points.