Can you show us some screen shots to help us.
In particular, I would like to see the Parameters To and Results From setup in the Main test and the input and output parameters as shown in the subprocess. "FolderName" should be defined in both places.
The following simple example works under 10.1 on my machine:
Set up a work field simply parses a fake XML payload into a property fl_primeXml.
The main test passes the input fl_primeXml parameter to the subprocess and expects a sub_CountOfOccurs property back.
The SubProcess only has one step containing an XPath Filter.
Similarly, the subprocess identifies the input parameter fl_primeXml and sub_CountOfOccurs is shown as an output property.
When we run this in ITR we see.
The Print Pre-Step simply invokes a script to see if the value exists or not.
_logger.info( "The value of the counter before calling subprocess is: {}",
testExec.getStateString("sub_CountOfOccurs", "This value does not exist") );
And this is confirmed by the properties panel in ITR right before the subProcess is called:
But what I would be interested to see in your ITR view are the properties right after the call to the subprocess. In my example, the property created by the subprocess shows up in the response.
And the JSR step that follows is also able to access the property and print its value in the log file.