How to connect two buses with an offset in Proteus?
I can't answer for Proteus specifically ( I don't use it) but a typical, indusry standard of dealing with "Bus Bundles" would be would be to connect to the same bus with with bus entry points label as:

A[0:31]  with B[2:31],B[0:1]  if you wanted to rotate the bits around.

or

A[0:31] with B[2:31],&lt;2*>C  if you wanted to stuff ground onto the upper bits assuming C would be grounded.  This is using prefix notation.

Note that labelling nomenclature may be different.