Web
Select the job from the Activity list
Click on the blue pencil icon in the Fields section
Here you can manage all the detail of your field in one go - edit field worked areas and completion information.
You have the choice to select all fields or choose field individually in the "Edit Multiple" column
When a row is highlighted as blue, changes made will apply to selected fields
Edit the user who completed the work by tapping on the name
Remember to tap "SAVE" at the bottom of the page to record changes!
Mobile
There is an option to "Mark all fields as complete" when a Field Job is selected from the Activity or To-do List. This will apply the completion information to all fields in the job.