Parent Child Help

Ok..i am looking to implement a listing site using this sofware, but I need to be able to have a person listing themselves check off their skill set by major category, and then select subcategories in a major category..they need to be able to check off multiple categories with multiple sub categories..and then later on somone needs to be able to search on these criteria ? Can this be done ? If so how ?

[Eric Barnes]

The parent - child extra fields allow you to go one level deep and each choice can only be one selection. For example if you are listing cars then you would have a parent of Ford and children of Taurus, Mustang, etc..