And that problem is normally fixed by including ADL, but in the OP's case that will mean 5 flight segments in the continent, which is 1 more than is allowed
(SYD-CHC-MEL-PER-ADL-SYD)

OP, if you are prepared to substitute AKL for CHC, then this would work:
...CGK-HKG-AKL-MEL-PER-ADL-SYD...

Another possibility, depending on when you intend to fly, is:
...SYD-CHC,AKL-PER-MEL-SYD... (surface segment between CHC and AKL)
The AKL-PER flight is seasonal only - during the summer months. And only twice a week - Saturdays and Sundays