Conditional Selection for Custom Fields Selected

When creating custom fields we would like the ability to be able to have a selection determine the next set of available selections and so on down the tree.

Example

Categories > One, Two

Locations > ABC, DEF, GHI, JKL

Selecting Category One only allows the user to select from Location ABC or DEF. Selecting from Category Two only allows the user to select from Location GHI or JKL.