To modify a business/department, open the business/department and then click on 'Modify'. Refer to the image below.
Now, you can adjust the details as needed. If you choose 'Save in the meantime', all data will be saved while keeping the window open. To save definitively when you're done, select 'Save'.
By clicking 'Cancel' or the 'X' at the upper right corner, you will return to the business/department field without saving any new data.