Value list across join table relationships

I am having difficulty generating a filtered value list from existing data.

These are the tables:

Patient

Facility

Account

Hospitalization

Each Patient is related to 0 or more Facilities through the Account table, which serves as a join table.

Each Hospitalization is related to one Account, and thereby to its Patient and to its Facility.

Each Hospitalization is also related to one other Hospitalization, which is its referring Hospitalization. (For example, if a patient is transferred from one facility to another.)

I am trying to create a value list that displays only valid referring Hospitalization candidates according to the following criteria: same Patient, earlier admission date.

My trouble is that it always wants to present a list for all Hospitalizations for all Patients.

My table occurrences (in anchor buoy) are as such:

pts__PATIENT;

pts_Patient_ACCOUNT;

pts_Patient_Account_FACILITY;

pts_Patient_Account_Facility_HOSPITALIZATION

pts_Patient_Account_Facility_Hospitalization_HOSPITALIZATION_ref

pts_Patient_Account_Facility_Hospitalization_HOSPITALIZATION_refCandidate

I have a layout based upon the TO: pts__PATIENT

Within that layout, I have a portal for pts_Patient_Account_Facility_HOSPITALIZATION

Within that portal, I have a field from the pts_Patient_Account_Facility_HOSPITALIZATION table occurrence named _kf_ID_hospitalizationRef that points to the referring Hospitalization. It is this field for which I am trying to create the value list.

The TO that ends in refCandidate is intended to define this value list

I have tried to start the value list from

pts_Patient_Account_Facility_HOSPITALIZATION and from

pts__PATIENT to no avail.

Any suggestions on how I can get the value list to recognize the patientID indirectly associated with the Hospitalization so that it can limit the list of selectable options for the referring Hospitalization? Any help would be much appreciated. Many thanks.