Is there a way to modularize JMeter tests.

I have recorded several use cases for our application. Each of them is in a separate thread group in the same test plan. To control the workflow I wrote some primitives (e.g. postprocessor elements) that are used in many of these thread groups.

Is there a way not to copy these elements into each thread group but to use some kind of referencing within the same test plan? What would also be helpful is a way to reference elements from a different file.

Does anybody have any solutions or workarounds. I guess I am not the only one trying to follow the DRY principle...