noturbulence

will be transiting through BKK en route to HKT - arriving in BKK on an international TG long-haul and transferring to HKT also on TG

but it seems that my connecting domestic flight (TG684) is actually marked and operated as an international departure, probably as it will continue under the same number then from HKT to Beijing

at least in flightstats it seems that the flight regularly departs from the international gates (e.g. C or D gates but not A or B)

so is my assumption correct and if so where will I clear immigration - in BKK or HKT?
I would think the latter but not sure at all

would I have to stay in the international gates area when disembarking from my international inbound to BKK and not follow the signs to domestic connections?
or does this nevertheless work as it were a regular international/domestic transfer?

and if this is actually handled as an international departure can I access the TG international departures lounge (booked in J)?

apologies if this has been asked and answered before but I did not find anything relevant using the search function

your help and advice is greatly appreciated

Tokyoite

You definitely need to clear immigration at BKK transit when transfering from international arrivals to a domestic departure.
There is a dedicated transit immigration for such situations.

You can only access the TG domestic lounges from the domestic departure area
= if you qualify (based on *A Gold status/business class domestic flight departure)

Thai-Kiwi

The 'good' thing about being on TG684 for the BKK-HKT flight is that OP should be able to select a seat in advance - not normally possible for THAI's domestic flights until OLCI opens at T-24.