MDX has variety of functions to support the user needs. MDX lacks the function to find the modulo operation.  But we can achieve the modulo operation by using the calculated member.
 
      Formula: number1 - (Int(number1/number2) * number2)
 
Sample code is below:
 
WITH
  MEMBER number1 AS 5
  MEMBER number2 AS 3
  MEMBER mod AS
    number1 - Int(number1 / number2) * number2
SELECT
  { mod } ON 0
FROM [Adventure Works];

Answered Forum Thread: MOD Function in MDX