Working with subform List of Values from global map lists

I have been improving navigation by compressing screen navigation using subforms (to multiple levels).  I have a need to use a list of values in a sub sub form and realise my ability to reference a globally stored value set in a previous script  ie. execution.setVariable("globalItemMap",globalItemMapTemp ) cannot be accessed in the sub-subform level via {{$itemParent.globalItemMap}} in the freeform item section of the single select properties.  I've tried a myriad of things, and cannot find any relevant content other than the following link: Sub-Form | Flowable Enterprise Documentation

At this time I am not prepared to load the list of values into its own Collibra register (as I am building an example workflow to demonstrate capability on a generic situation), but will need this question solved for the next development.  A solution should be able to reference that list of values from whatever level of sub-form we choose to use the specific form at.