How can I filter this report with user name?

I am using below recipe to create a SAIL report. How can I filter this report with user name? Please note that I have added a column "Assign To" in the portal report that display's tp!owner information. I was able to add the user picker to the below recipe, but I am unable to filter the grid based on user that is being selected by the user picker control object.

forum.appian.com/.../SAIL_Recipes.html
Thank you for your help in advance!

OriginalPostID-147970

OriginalPostID-147970

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