Copy values from a sibling entity to a child entity

Summary:

Content (required):

I have an entity called the narrative that has a sibling called the project and a child called the nibling.

Global

the project

the narrative

the nibling

There is a relationship between the narrative and the project such that the project knows the narrative and the narrative knows the projects that go with each other.

The relationship between the narrative and project is many to many (each project can have several narratives and each narrative can have several projects).

Due to the inability for BI Publisher Desktop to use anything other than containment relationships in a repeating region, I can't print the projects that go with each narrative on the form.