The ADL int terminal dep zone has been redeveloped in the past few months, now very modern.
First go to check in, as with dom pax.
Go through dom security.
Go to QP/J lounge if you want.
Go downstairs to outgoing immi and int security screening.
Then go upstairs to the closed off area, which is really just the dom zone, but closed off.
Think that the flight from SYD is an overnight layover, to meet the 330 that comes empty from where ever, to fly to DEL
Edit: strange, on a Wed, in Apr 2022, if you put in a dummy booking, it puts you through ADL -> SYD, SYD -> BKK, all with QF, then from BKK -> DEL with TG.
Few days ago, direct flights did come up, then maybe someone changed their mind, for 7 days, when I did a dummy booking, it all sent pax via BKK with TG, as we know, no QFF points or QF SC earned this way.
Sun, Mon, Tue, they put you through ADL -> MEL -> DEL.
Maybe in the meantime, while we muse about it, they (QF) have changed their minds about ADL int flights again
Checking Oct 2022, also they put pax through MEL.