We want to extend the bug work item template with a new field called Found In Iteration. This field, what a surprise, should contains the iteration the bug was found in. But when I created the new field of type TreePath, I got an error when importing the process template into the Team Project Collection (TPC) stating that TreePath is only a valid field type for IterationPath and AreaPath fields.
Looking at that I'm wondering if there is at least any way to add a field to a work item template that uses the iteration path as data source and stores the selected value in another field (e.g. FoundInIteration).
This is not possible. There can neither be custom fields of type TreePath nor fields refering to System.IterationPath.