DSGROUP() option is only used in the Post-Install Bind process when the DRDA Remote Binds option is set to YES.
The generate bind task uses DSGROUP to look for remote subsystems that are in the same data sharing group as the local subsystem so that it does not generate bind statements for those remote subsystems. In other words, it allows Remote package binds to be skipped and a warning is issued:
**** WARNING**** Parmlib member ' || taskset || , defines remote location ' || setloc || '/' , | setlocid
**** in the same data sharing group (' || setdsgrp || ')',| ' as local subsystem ' || ssidsave || '.'
**** Therefore, ' || setloc || , will be omitted from remote DRDA package binds.'