If you use the Content Migration Admin Portlet in MWS, you can choose the option to export permissions. (The same is true if you use Deployer).
Attached is an older internal document describing xmlImport in a bit more depth.
Hope this helps.
–mark
FYI:
In 8.2, we’ve significantly enhanced the ability to export many runtime assets (pages, permissions, portlets, skins, shells, etc…) into Designer using new project types.
xmlImportFAQ.html (42.6 KB)
#webMethods-BPMS#MWS-CAF-Task-Engine#webMethods