Hi Amber, I know this was a year ago, but I searched for this issue too and did not find a good answer on the boards, so I thought I would post my solution. It is not 100% perfect but 80%.
Fields/Relationships
Create the 2nd Table as the Join. So you will have Projects Table and Related Projects Table.
Create a basic relationship - Projects to Many Related Projects and pull over the lookup fields. I would rename those Master Project - Name, Master Project - Manager, etc.
On the Related Projects Table, create a multiple choice field that pulls it's choices from another table. Use the Project Name field from the Projects Table.
On Projects table create a report link, Project: Name to Related Projects: Master Project Name
On the Related Projects Table create a report link, Related Projects: Project Name to Project: Name
Related Projects Form:
Multiple Choice Project Name (can rename on form to Related Project) - for Data Entry
Report Link (link to record, not the report option) - for viewing
Master Project Name - this will be read only and for reference.
Projects Form:
Add Related Project Button
Projects Table Report Link
The user will click Add Related Project Button on the Project form. On the Related Project Form they will select from the drop down. They will save and on return to the Projects form the report link will show all the related projects. They can keep adding more as needed.
Hope this helps someone!
