Sam, I followed the video and got it to work when displaying in a Table. 688 is the number of inspections up through today for 2017.
Using the following:
Inspections = COUNT('ISN orders'[oid])
SameLY Insp = CALCULATE(COUNT('ISN orders'[oid]), SAMEPERIODLASTYEAR(Dates[Date]))
Insp YTD SameLY =
VAR LastInspectionDate = TODAY()
VAR YTDInspections = TOTALYTD(COUNT('ISN orders'[oid]), SAMEPERIODLASTYEAR(Dates[Date]))
IF(MIN(Dates[Date]) <= LastInspectionDate, YTDInspections, BLANK())
NOTE: the reason I used TODAY() instead of MAXX like your example is we have some orders that have been booked early for Nov and Dec, so it was pulling the entire year in when I only want the inspections up to today (Oct 30, 2018) and compare to Oct 30, 2017.
However, I want to show the total for 2018 (786) vs total for 2017 (688) up to current date. But when I try to show the sums for the ytd, I get the totals from the entire year in 2017 (784). I need it to read for Insp YTD SameLY = 688.
I feel like I am close.
To clarify, my ultimate goal for this matrix is to show the growth rate through the current date of 2018, while the past years will be the growth rate for the entire year. Because in 2018, the growth rate for inspections is 14% (through 10/30/2017 = 688 inspections vs through 10/30/2018 = 786 inspections).