The User Departments list in FinOps (for assigning Departments to individual Users in FinOps) is a entirely separate list of Department Codes.
Therefore any 'Code' added to Financials will not automatically add or appear in the User Departments Lookup list.
Instead you have to manage the Departments via a System menu.
It is possible to do this all within the Financials Application within Workspace, providing you are an administrator with the correct permissions.
Follow these steps in Financials:
To Manage the Departments Lookup list
Click System, Settings, Departments
From there you can then see a list of your existing Departments and have the option of adding New or Edit (or Delete) existing records.
To Assign the Department(s) to a Individual User
Click System, Security, Users
Locate and highlight your user record, then click Edit
On the User record click the Links tab
You will then see a User Departments window section where clicking Setup will allow you to select and/or remove Departments for this User.
Click Save to confirm changes
Repeat for all users are required.