Dax Conditional Formatting to Highlight Last Value

[JanaeWalker864]

This is an illustration of a forecast. Forecast as of date which comes from my historical forecast table represents the date in which a forecast was updated(In this case the forecast is updated every month) and the matrix displays those values in columns by forecasted month using my Date table. I would like to be able to highlight the last value updated from that month but I can not wrap my head around the logic to apply in a dax formula.

[JanaeWalker864]

This is what I compliled however, I received this error message 

Measure Conditional Format =

VAR __ForecastMonth = MAX('Historical Forecast'[Forecast As Of Date])

VAR __Date = MAX( 'Date'[Date] )

VAR __MaxDate = MAXX ( FILTER( ALL( 'Date' ), 'Historical Forecast'[Forecast as of Date] = __ForecastMonth ), [Date] )

VAR __Result = IF( __Date = __MaxDate, 1, 0 )

RETURN

MAXX('Historical Forecast', __Result)

A single value for column 'Forecast as of Date' in table 'Historical Forecast' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to a single unit

[Greg_Deckler · Accepted solution]

@JanaeWalker864 

Measure Conditional Format =
VAR __ForecastMonth = MAX('Historical Forecast'[Forecast As Of Date])
VAR __Date = MAX( 'Date'[Date] )
VAR __MaxDate = MAXX ( FILTER( ALL( 'Date' ), 'Historical Forecast'[Forecast as of Date] = __ForecastMonth ), [Date] )
VAR __Result = IF( __Date = __MaxDate, 1, 0 )
RETURN
__Result

[Greg_Deckler]

@JanaeWalker864 Tough to be exact since I have no idea about your table and column names. But maybe something like:

Measure Conditional Format = 
  VAR __ForecastMonth = MAX('Forecast'[MonthYear])
  VAR __Date = MAX( 'Dates'[Date] )
  VAR __MaxDate = MAXX ( FILTER( ALL( 'Dates' ), [MonthYear] = __ForecastMonth ), [Date] )
  VAR __Result = IF( __Date = __MaxDate, 1, 0 )
RETURN
  __Result

You can then create a conditional formatting rule based on this measure where 1 is the last date in each forecast month.