When talking about gold production, we are primarily talking about gold mining; which country has the highest output of gold ore from their mines. This output is specifically within the home nation, and not including investments in foreign nations through a multinational corporation.
Many of these countries will have their own authorised and accredited refineries or mints to produce a range of bullion or doré (gold/silver mix) bars and coins for resale. This could be to national banks to form part of a nation’s precious metal reserves, or it could be to the wider public market, but this isn’t considered part of their overall gold production.