XF 2.2 can Prefix or Custom thread fields be presented in a conditional and/or hierarchical system?

Is this at all possible?
...should this be a feature request?
...or is this squarely in the realms of 3rd party add-ons and I should move this into a request over in that area?

To clarify, it would make it so that either
the pull down choice of field 1
then changes the pull down options for field 2 (or if a choice 2 was required or not)

or in a single field situation the pull down was simply sorted into a hierarchical system to go thru a large about of choices quickly in a intelligent format.