HCM CDS View for OM and structural profile / authorization

[pfoehn]

Good day,

I am looking for a solution to implement the following business requirement with CDS VIEW ENTITY:
=> CDS View displays "all employees" a specific "adminstrative assistant" is repsonsible for. The "administrative
assistant" is assigned with a "Role" to a certain "OrgUnit" in the "OM model".

Technical Steps:

1) determine the administrative assistant (user) running the cds: => $session.user

2) determine PERNR of $session.user: => PA0105

3) determine organisational assignment as administrative assistant (role Z20) in OM model:
=> HRP1001 OTYPE='O' RSIGN='B' RELAT='Z20' SCLAS 'P' SOBID= PERNR =>ROOT_ORGEH

4) Traverse "down" recursive all OTYPE 'O' with Root Node ROOT_ORGEH found in 3)

=> CDS View with "define hierarchy"
define hierarchy zhrct_b_orghierarchy with parameters iv_orgeh : ROOT_ORGEH

5) Select all PERNR for the OrgUnit found in 4): => PA0001-ORGEH

The problem I face is:

It is not possible to use the value of a "projection" field (ROOT_ORGEH) as an Import Parameter for the Hierarchy View
define hierarchy zhrct_b_orghierarchy with parameters iv_orgeh : ROOT_ORGEH
(known restriction of CDS).

Is there another solution to this problem?
Has SAP a "standard" CDS in VDM HCM?
A "ABAP" CDS (define custom entity) is not a solution as the CDS View will be used in a SAPUI5 / Fiori Elements / RAP
App. I do not want to implement all the "READ" "FILTER", "SORT" etc. functionality, but my intention is to use (RAP) SADL Framework to do that.

Thank you for your much appreciated comments.

Kind Regards

Paul