I want to set the value in the second field of OBX-5, or OBX-5-2. My schema is not broken down to that granular level, so I can't just click OBX-5-2 to populate it. I tried a few variations without success.
target.{PIDgrpgrp().ORCgrp().OBXgrp(1).OBX:ObservationValue(1).2}

target.{PIDgrpgrp().ORCgrp().OBXgrp(1).OBX:ObservationValue(1)(2)}

target.{PIDgrpgrp().ORCgrp().OBXgrp(1).OBX:ObservationValue(1.2)}
  Any ideas?