I have a similar intl-dom transit coming up, flying VIE-BKK-CNX on one ticket. I have almost 4h of transit time and noticed that none of the lounges in the Domestic section of BKK seem to have showers.

Would I be able to somehow access the lounges in the international section and only then proceed to the domestic wing? I forgot if intl. arrivals and departures mix at BKK (like SIN) or are entirely separate (like HKG).