Dynamic measures based on multiple slicer selection.

awitt 

I took a pass at a solution but I have a question.  Right now I am showing the highest date so if you are looking at order 1 ordered date it will show 1/2 but if you look at order 1 with the item it will have a different date for the two items.

First we make a couple of tables using all available status.  Doint it this way insures we always have the full list.

Status1 = DISTINCT('Table'[Status])

Status2 = DISTINCT('Table'[Status])

I have a couple measures to test the dates that are coming from the slicers (Date1 and Date2)

And finally a meaure to do the calc.

DateDiff = 
VAR FirstStatus = SELECTEDVALUE ( Status1[Status] )
VAR FirstStatusDate = CALCULATE(LASTDATE('Table'[TimeStamp]),'Table'[Status] = FirstStatus )
VAR SecondStatus = SELECTEDVALUE ( Status2[Status] )
VAR SecondStatusDate = CALCULATE(LASTDATE('Table'[TimeStamp]),'Table'[Status] = SecondStatus )
RETURN DATEDIFF( FirstStatusDate,SecondStatusDate,DAY)

I have attached my sample .pbix for you to look at.