How to target people born in one country but living in another?

target by language they speak

Afrikaans Language
Zulu Language
Xhosa Language
Swati Language
Sotho language

yeah, I know they speak english, so dont target that as so do australians!

I just want to know why you target South African people? Are you from Africa?

I would say it depends on your target - is the only criteria only South African expatriate based in Australia? Or for you it's also important their marital status and other factors (in this case if you are launching some specific service like dating).

I would suggest one a little bit different idea. When people are moving to foreign country, most if them still are interested in their native country, most important local events, etc.
I am pretty sure that most of Australia based South Africans are regular readers for biggest South African local news portals. So if you approach biggest South African news portals and will try to buy their Australian traffic, you can be sure - you will get Australian South Africans Maybe sounds complicated, but its a really effective way which can bring you good volumes.

Another one thing - not all people are gathering on Facebook. There a lot of specific forums and websites for expatriates' communities..

Here's a simple keyword search:

I'm really surprised FB left this demographic search out of their advertising options unless I missed it somehow this is like the biggest targeting criteria there is after targeting perhaps gender, age, education level and income bracket among perhaps a few others like occupation etc. Targeting expats is a real winner that FB really ought to have added from day 1 or should figure out how to add now. This is a big loss in profits for many (and for FB as well if they care lol)... Well we'll see...