This wildcard is replaced by the output value of a node whose NodeID is used. The node ID of each node that outputs an output value can be copied into the clipboard via the edit palette within the stream designer.
The value of the NodeID will be the same as common outputs like {job.destination}, {job.proxy} and so on.
The function here is the same as one can get by using the wildcard {stream.last_result}.
The wildcard is used in the following ways:
Use an action like Regex Apply
Define parameter
Fetch the result with the syntax {stream.last_result}
The result in this case is equal to {node.result.?}.
The difference here is, that this value can be overwritten by another node which is not happening when using {node.result.?}.
In case you are using a Job File Copy Action between the Regex Apply and Temporary Variable action the result will be the following