Modelling hierarchy information

I am creating a dimensional data model to store Project management data. I am receiving 3 file input file

1. Region.dat - Has Region details

2. Project Detail.dat - Each record contains details about each program or project or subproject

3. Project Cross Reference - Cross reference file to build the hierarchy for Program, project and Subproject. One project can reside under
more than on program and subproject under more than one project

I am creating 2 dimension to store Region and Project detail (Excluding effort)

How do I store the cross reference/hierarchy – Bridge table, as key columns in fact table?

Input Files

Region - (Region information)
Region ID
Region

Project Detail - (Program/project/Subproject information)
ID (Can be program/project/subproject ID)
Project Name
Manager
Status
Progress
Sart Date
End Date
Approved effort
Actuals effort

Project Corss Reference
Program Id
Program Name
Project Id
Project Name
Sub Project Id
Sub Project Name