Category is returned from Find Incidents as per:

Then what you have to do is do a double FOR LOOP, because categories are arrays(as you can have multiple categories per any one incident).
So I would do a first For-Each block through Workflow.FindIncidents.FoundTasks.Items (which is an array of all the found tasks information)
Then a 2nd For-Each block through Workflow.For Each Block 1.Item.Category Names
And then inside of that you could pull out each category per incident.
Let me know if makes sense.

-Shaun
--Shaun Roberts
Principal Engineer, CX
shaurobe@cisco.com