if ($host = "hub.mydomain.com") { rewrite ^ https://www.mydomain.com/pages/solutions/hub/index.html permanent; }
if ($host = "hub.mydomain.com/save") { rewrite ^ https://www.mydomain.com/pages/solutions/hub/save/index.html permanent; }
This question has been answered by smorris. See the first response.
location ~ ^/save { return 301 https://www.mydomain.com/pages/hub/save/index.html; }