How do I unlock access to Jurassic Park 2 and Jurassic Park 3?
According to this Gamefaqs thread where someone asked the exact same question, in order to access the Jurassic Park 2 and 3 levels you need to go to the Jurassic Park hub go to the helicopter and go to the Lost World. When you are there you will find a boat which will take you to Jurassic Park 3 in the Lost World hub world.