How do I create a context sensitive DFF that ties to a person EIT?

We created a custom person EIT to classify contingent workers.  We have 4 different classifications.  Two of these have require additional information with multiple segments.  I need to know how to create a context sensitive DFF that opens one of the two custom DFFs based on the value chosen in the primary person EIT.  We chose to use a person EIT rather than person types since we want to use the person EIT in all legislations and also incorporate the classifications into our corporate heading reporting.