Step 1: Select the shift/shifts you want to update the Cost Code within the Productivity View. Then Click "Bulk Productivity" 
Step 2: Select the Cost Code you will apply. In the Time box to the right, input 100 and choose % as the type. Click "Apply," and all selected cost codes will be updated.
You can only apply one cost code when working with an open shift.
Tip: This process will also apply when updating other productivity items within the account, including Classification and Locations.