[af_vet_rr]

So, a white from South Africa would be a South African-American?

Would somebody from South Africa living in Brazil be a South African-South American?

[luvbach1]

Would somebody from South Africa living in Brazil be a South African-South American?

I think you were being facetious; but no, because there is no nation called South America but there is a nation called the United States of America (also known as America.)However, the person you envisioned could be called a South African-Brazilian.