Get Last Two Chars from End of String:
substring(., string-length(.) - 2)
Get Left of String Minus Two Chars:
select="substring(., 1, string-length(.) - 2)"
Notes:
- The 1st Param is String
- The 2nd Param is Start Position
- The 3rd Param is How Many Chars to Return
- Starts counting at 0 not 1