How do I pass a value out of one dataflow and into another dataflow?

I'm trying to pass a value that's set inside of one dataflow into another dataflow, but I can't get the variable to show up in the Output section.

I've noticed that if I take a workflow that has the ".Wf" extension, the variable shows up in the Output section.

But with the newer workflows that have ".Wfs" extension, the variable does not show up in the Output section

And Centerprise does not allow me to create a workflow with ".Wf" extension

Here's what I have inside the dataflow

And here's the Variables item for the dataflow

Here's the version of Centerprise that I am using