In JENKINS-24626, we agreed to create a "Downstream build of" build selector.

This works in the case that you always want to use the Last successful build which matches the upstream project.

IMHO, the "Downstream build of" selector should be additional to the other build selectors.
E.g. In our build environment we (mostly) need the case where we want to select:

• The Last promoted build
• From a Job which has is a "Downstream build of" a given configuration
• Possibly some other "Parameter filters"

So, I think we actually have three selections which can be combined (independently):

1. Build status ("Last successful build", "Last saved build", ...)
2. Build sources (i.e. "Downstream build of")
3. Build parameters (i.e. "Parameter filters")

The first two should be configurable as "build parameters" for Copy Artifact Plugin:

1. Build status via parameter: *Build selector for Copy Artifact"
2. Build source via parameter: *Source selector for Copy Artifact"