You can go to the object nested fields the way you have described. You have a couple of options:
1. If($Customer <> Null, Catch(GetHyperLink($Customer.$C_AccountOwner),NULL), "")
2. If($Customer <> Null, Catch($Customer.$C_AccountOwner.Name),NULL, "")
You would need to use the catch function in case there's no owner.
Please let me know if that worked.