how to compare data-group values

e.g.

 config

[root@ve11a:Active:In Sync] config  tmsh list ltm data-group internal sit-iolb-t1-zolb2-ser-c1-v8-443-vsrv-ma
ltm data-group internal sit-iolb-t1-zolb2-ser-c1-v8-443-vsrv-ma {
    records {
        epsir515.unix.srv.amit.com.au { }
        epstammonitoring.test.unix.srv.amit.com.au { }
        sitws1.olb.srv.amit.com.au { }
    }
    type string
}
[root@ve11a:Active:In Sync] config  tmsh list ltm rule qux
ltm rule qux {
    when RULE_INIT {
  if { !([TMM::cmp_group] == 0 and [TMM::cmp_unit] == 0) } { return }
  set sbj "sitws1.olb.srv.amit.com.au"
  if { [class match -- $sbj eq sit-iolb-t1-zolb2-ser-c1-v8-443-vsrv-ma] } {
    log local0. "match"
  } else {
    log local0. "not match"
  }
}
}

 /var/log/ltm

[root@ve11a:Active:In Sync] config  tail -f /var/log/ltm
Apr 21 21:48:19 ve11a info tmm[13593]: Rule /Common/qux : match