CAD Studio AutoClass
AutoClass is a tool for classification (grouping) of DWG objects in AutoCAD. It sorts selected objects into individual categories based on their common property - like Elevation, Area, Length, Volume, Radius, Rotation, etc. The individual categories (classes) are represented by colors (multiple palettes are offered - rainbow, hydro, green, pastel...) or by automatically created layers - like AUTOCLASS_RADIUS_10_19, AUTOCLASS_RADIUS_20-29, etc.
You can use AutoClass e.g. to color 3DFACE terrain models, dissect points according to their elevations, mark parcels by their lot areas or solids by their volume.
Available for AutoCAD 2016-2014 but other versions will probably also work.