If there's an article written by 'Bob Smith' for example, and I have taken a quote out of Bob Smith's article: 'The sky is blue' (Smith, 2014). But then, in Bob Smith's article, he quoted Jane Jackson 'Grass is green'.
I want to use Jane Jackson's quote in my work, so, I've written, Jane Jackson said 'Grass is green'. But how do I write the intext citation? Who am I citing, Bob Smith or Jane Jackson? And who do I put on my reference list?
Ideally, you should try to find the origional source. The work you are quoting from should reference it. However, you can reference something as "cited in" another work.
So, you would say something like (Jackson, 1994 cited in Smith, 2014). I think, for your final reference list you would only include Smith as a reference.
Possibly the best resource known to man for Harvard Referencing - it includes the answer to your question amongst many others that you haven't even thought about yet http://libweb.anglia.ac.uk/referencing/harvard.htm