Share / Export eclipse working sets

You can try and export (as in “copy to another people workspace metadata directory”):

</path/to/.metadata>\.plugins\org.eclipse.ui.workbench\workingsets.xml

This is the file referencing your working sets.

z0r adds in the comments:

my team mate replaced his workingsets.xml with my version of the file, and it worked well.
However, you must exit Eclipse before replacing the file, because Eclipse will overwrite it with the old version when it exits.
I think you only need to do this once.