Exposing a Path from a Node Group

Hey, I created a Node Group that saves specific passes that I want from my render. I guess there is no way to expose the Path that it saves them to, so I can easily reuse this Group in different scenes?

It does not look like it. The best you can do is specify relative pathing then the output will end up in the same folder where the .BLEND file is saved.

Hmm. I wonder if you can apply a py driver to that field. Would be handy to define path as a variable.