You can use explicit subdomains however you will not be able to use wildcard/dynamic subdomains. What others do in this case is pass a unique variable over via the state parameter and redirect to a generic hub, the hub can then route to the correct subdomain based on the state parameter.
I am integrating MYOB Account Right API for our ASP.NET site and need few things to be clarified. When we are registering an application, can we specify the Redirect Uri to be dynamic such as "~/Accounts/MYOBSetUp.aspx". We have several clients in few servers. Hence we cannot have a static redirect uri. I would like to get your insight on this regard. At the moment the only workaround I could think of is registering the App for each server with relevant Redirect Uri.