Should work the same provided that windows are not maximized and that your application window is large enough for both windows.
Thank you for your reply Phil
The problem is that the second window always opens in the same "upper left" corner of the application window as the first window.
If this happens due to the application window not being "large" enough for both FM windows, how can I make sure, before opening the second window, that the application window is large enough?
Sorry for the rather daft questions but I've been working on the Mac for 30 or so years. :-)