I'm not quite following what you are doing but I'll explain how to do what I think you want.
In the Read File and Write File operators, you can't specify the name of a connection as a parameter, you must enter the name of a connection artifact.
In the connection artifact, however, you can specify the path by entering a parameter name.
It is probably easiest to define a separate configuration artifact for Dev, QA and Prod. In each of these, create the same two entries: staging and datamodel. But, enter the appropriate location for each group as the values for these entries.
Then when you run the dataflow, simply specifying the proper configuration artifact will set the dataflow for the desired group.
Note that before running the dataflow, you must associate the configuration artifacts with the dataflow. In the Dataflow > Build ribbon bar, use the Configuration References button and add all three configuration artifacts.
Thanks John! Just went through an onsite Expressor Traning last week and heard your name alot.
What I was actually looking for was for the parameter values to be present in the drop down menu on the file connection artifact
My parameters do not appear, so that was throwing me off. I went ahead and manually typed them in and ran the dataflow. That worked just fine.
Is there a reason for having a seperate Configuration artifact for each environment instead of setting up 3 Value Sets (Dev,QA,Prod)? I have mine set up with 1 artifact, 3 Value sets and it worked the way I was expecting.