Map how to iterate over a map and return keys and values?

Question

C++ / C#

I can't figure out how to pass through a map like map>
Example

map<string, map<string, string>> getLocaleVal(string s)
{
    map<string, map<string, string>> loc = {
           {"menu_main"}, 
                {"action_menu", "translate"}
};
    return 0;
}