nested hiera lookup

hieradata.yaml

group_allocation:
    devcoreoeml030.matrix.sjrb.ad: smokestack
    devcorebrml030.matrix.sjrb.ad: smokestack
    devcoreesbl030.matrix.sjrb.ad: smokestack
    devcoreoeml091.matrix.sjrb.ad: the091
    devcorebrml091.matrix.sjrb.ad: the091
    devcoreesbl091.matrix.sjrb.ad: the091
    devcorepptl003.matrix.sjrb.ad: dev_master
    tstcorepptl003.matrix.sjrb.ad: tst_master
    devcorepptl918.matrix.sjrb.ad: brett_sandbox
    devcorepptl919.matrix.sjrb.ad: brett_sandbox

groups:
  core030:
    data:
      tag: smokestack
      owner: bcornies
  the091:
    data:
      tag: brettstack
      owner: bswift
  brett_sandbox:
    data:
      tag: brett
      owner: bswift

my_group_name: "%{hiera('group_allocation')}.%{::fqdn}"
my_group: "%{hiera('groups[%{hiera('my_group_name')}]')}"
#my_tag:  ...