Unfortunately, I fear that is going to be bounced by CX. I don't think they will allow MEL-BME and PER-MEL on the same ticket - that falls foul of the "one transcon in Australia" rule.
Code:
Q. Within Australia only one Nonstop/Single plane service flight is
permitted between the following points
BNE/CNS/SYD/MEL - PER
MEL/SYD - DRW
MEL/SYD - BME