That depends.
If the credits are cleanly divided by category (for example, X is an actor and Y is a production designer), the easiest way is to use the "name split" option.
If the credits are more messy (for example, two different actors with the same name have their credits intermingled), then you'll need to choose the "correct" option for the affected filmography categories. Once you have the affected credits, you should choose the "show name" check box. You will then need to add Roman numerals to the names as necessary; for more details, see the guide to name formats.