CBSubs exports the main table, not tables related by JOINs in the query.
You would need to do run an SQL query with the corresponding tables JOINs.
That could be run manually in e.g. PhpMyAdmin, or automatically using a mysql client.
Alternatively you could export plans and users, and do the table-lookups to combine them in your spreadsheet software.
To see the SQL query used to display the list of subscriptions, including the table-JOINs, turn site debug on in System/Joomla Global Configuration, and in System tab, turn System Debug to on. That will display a footer on *all* of your site and admin backend (to avoid normal users seeing that you can previously change the access level of the Joomla Debug plugin).