I believe "nah, yeah" is used in an analogous way, but in my experience it's less commonly said than "yeah, nah".
Shall we help Dave move his fridge up four flights of stairs? "Yeah.... nah".
"yes, actually no"
"no, actually yes"
Rephrasing it as yes, 'actually no' makes it sound like the speaker is indecisive which yeah nah does not communicate. It's a a social nicety to smooth over hurt feelings.
That of course is until you use it with an affirmative 'yeah nah yeah you're right' or similar.
Nah, yeah = Yes
Kiwi's also do the same..
> You're not going on Wednesday?
I think it completely throws that rule of thumb out the window. Both "Yeah, nah" and "Nah, yeah" would seemingly be affirmative. To disagree would require a longer response.
Likewise if they said "You're going on Wednesday right" you could say "yeah" but you can't say "No", you must say "no, I'm going on Tuesday" or "no, it's my kid's birthday" or "no Clive is".
As far as I can tell, a sibling comment has it right: the last word signals the intent (modulo tone, sarcasm, etc).
edit: USA west coast English
A judge in a court case should be saying "yeah nah" when they come down in favor of the other side; an American who uses many words because it is rude to say "no" is nevertheless just saying "no".
"Yeah, nah" would typically be in agreeance of a negated question e.g. "You don't like Game of Thrones either?"
Edit: Heck, even if someone responds simply "Nah" to that question it's not clear what they mean without a further followup sentence or the tone in their voice.
I don't know if it's just Australians or other English speakers, but we definitely have really confusing spoken semantics around affirmation of negated (or even negative outcome) questions.
My answer is "use a full sentence". If they insist on using "yes" or "no" because the answer is too long, I say "you can say "I do" or "she isn't", that isn't too long is it?
But if they promise they just want to know how people use "yes" and "no" while communicating and they really really won't try to use it, the answer is it's "yes and no agrees with the main verb in the full sentence of the answer _unless_ the question used a negative verb, in which case the only valid response is 'no'".
If necessary, I can explain: The reason this works is because if you have a question with a negated main verb, the questioner is making an assumption, and you need lots of words to contradict a person's assumption to set them right. Therefore "no" means "your assumptions are validated", whereas "no blah blah blah blah blah" means "let me destroy all your assumptions and rebuild the world in this fashion".
Since I speak with so many non-native speakers, I tend to speak like this automatically. Not every language has words for "yes" and "no".
This song will clarify it from an Aussie perspective: https://www.youtube.com/watch?v=nyadntqXjn4