After importing contacts from an Access database, I need to view them in the By Category view. If a contact has multiple categories blue, auto, and radio, for example Outlook displays that contact under one category titled blue, auto, radio instead of displaying three separate categories. How can I fix this?

In your Access database, change the data in the field that holds the category information so that it uses a semicolon as the delimiter rather than a comma. After you import the data, the three categories separated by semicolons in the Access database will appear in Outlook as three separate category groups, and a contact that has three categories will appear in each of those three category groups.