TeamCity and TeamCity Hub integration

Hello, 

I'm looking into trying to connect Teamcity with TeamCity Hub to enable LDAP authentication for multiple domains (As this doesn't currently work directly in TeamCity when setting up LDAP).

I'm slightly confused however how the integration actually works. I've connected my TeamCity instance with a TC HUB instance successfully. But I'm having a few issues. Firstly, when I try and synchronise TC with the HUB it doesn't pull in any of the groups associated with the users in the HUB into TeamCity. So although a user is created, they have no groups other than the default ones (Even though in the HUB I have manually added groups to the users that also exist in TC). Another issue is that it doesn't seem to pull in the groups that are associated with the user in AD from the LDAP server into the HUB. 

Another question I have is, will I have to migrate all my TC projects into the HUB? 

I was hoping that I could use the HUB as the authentication method for my TeamCity instance, so it would pull in all the groups associated with the users when they login and then give the user in TeamCity permission to view certain projects that exist in TC based on those groups that they are in. Have I misunderstood how the HUB works?