Derived/Filtered Multiselect Picklist

[Anonymous]

I've been searching for a couple of days, but have not found any solution for my problem. I would like to be able to have a 'Dynamically Filtered Multiselect Picklist', but have not been able to find any way for this to be accomplished. Here is my scenario:

In our environment, we have a "Test Plan" workspace, which generate and manage "Test Items" on another workspace. We want to be able to use the "Test Plan" workspace to delete records from the "Test Items" workspace. BUT, we want to only show those records for the "Test Plan" being edited. I can use a normal Filtered Picklist, but that would require a user having to repeatedly edit the "Test Plan" to select one record at a time. So, I'm trying to figure out how we can have one single-select picklist populate a multi-select picklist.

Here is a different method of explaining my situation:

Test Plan Workspace

Test Plan 1 manages Test Item 1, 2, 3

Test Plan 2 manages Test Item 4, 5, 6

Test Item Workspace

Test Item 1 managed by Test Plan 1

Test Item 2 managed by Test Plan 1

Test Item 3 managed by Test Plan 1

Test Item 4 managed by Test Plan 2

Test Item 5 managed by Test Plan 2

Test Item 6 managed by Test Plan 2

When editing Test Plan 1, populate a multi-select picklist with Test Item 1, 2, 3, but not Test Item 4, 5, 6.

I hope I've explained it well enough, if not I can always clarify. Anyone have any thoughts on how to accomplish this, or should this be a request for a future enhancement?