ODR pass on entity using groovy based on row data

Summary:

We want to create an ODR rule in Groovy (to reclass movement data across data sources), which uses the entities in the rows as entity selection.
We can get the list of unique entities from the form using "operation.grid.dataCellIterator().each".

The issue is that we cannot get the entities passed on to the ODR at runtime (they won't show up).
Does anyone have a way to do that? We do not want the users to select the different entities manually.

Currently they select a "user variable" in the POV which is a parent member and all children of that parent are shown in the form.