In order to view and purchase commercial licenses with multiple accounts, you need to add every account to your licensed account.
You can do this by following the steps below:
Access the Steamworks site with your already licensed Steam account and click the "Users & Permission" tab at the top.
Make sure that you fill out all the required information regarding the account that you would like to add and tick the box at the bottom before clicking "Add User".
Once you have successfully added the account, the appropriate flags will be activated and the commercial licenses will become visible to that account.