Measure to return multiple values

Datafruit This is essentiall MTBF linked below, essentially:

previous transaction datetime column = 
  VAR __curTrans = [transaction datetime]
RETURN
  MAXX(FILTER('Table',[transaction datetime] < __curTrans),[transaction datetime])

and

previous transaction datetime amount column = 
  VAR __curTrans = [transaction datetime]
  VAR __prevTrans = MAXX(FILTER('Table',[transaction datetime] < __curTrans),[transaction datetime])
RETURN
  MAXX(FILTER('Table',[transaction datetime] = __prevTrans),[current transaction amount])

See my article on Mean Time Between Failure (MTBF) which uses EARLIER: http://community.powerbi.com/t5/Community-Blog/Mean-Time-Between-Failure-MTBF-and-Power-BI/ba-p/339586.
The basic pattern is:
Column = 
  VAR __Current = [Value]
  VAR __PreviousDate = MAXX(FILTER('Table','Table'[Date] < EARLIER('Table'[Date])),[Date])

  VAR __Previous = MAXX(FILTER('Table',[Date]=__PreviousDate),[Value])
RETURN
  __Current - __Previous