You can connect and post to as many Facebook accounts, pages, or groups you'd like, and this option is available on all plans (Starter, Pro, Business, Agency).
One Facebook Account
If all your pages and groups are on one Facebook account, simply connect the account to Postradamus from Settings > Connections > Facebook and you're good to go. You will be able to select any page or group you'd like to schedule your lists to in the final step (Export).
Multiple Facebook Accounts
If you're using more than one Facebook account, you can create a separate Profile for each of the accounts.
In the top-right corner, click on Master Profile and click New Profile. You can also go to Settings > Profiles > New Profile.
1. Choose a Profile > New Profile
2. Settings > Profiles > New Profile
This new profile can now be connected to a new Facebook account, and your Master Profile will be connected to your default Facebook account.
To connect more Facebook accounts, just create more Profiles!
What if I have more than one Twitter/Google+/LinkedIn/... account?
Same thing applies!
Every profile can hold one Twitter connection, one Google+ connection, one Facebook connection, and so on.
If you have more than account, simply create enough Profiles to connect your accounts to Postradamus.