CDO can crop a netcdf file in terms of latitude and longitude as long as they are defined in a standard way, and I know that NCO can cut out a subset of a netcdf file along any dimension if you know the range of indices that you want, as stated in the answers to this related question:
Is there a way to crop a NETCDF file?
However, I was wondering if the ncks hyperslabber can work directly on the values of the dimension, rather than the index values?