Am using the grid feature in the form to show multiple values from the database/

To save someone else too many hours of work, I'm going to record how I finally got this to work. All variables mentioned are multiples. The first rule returns the values for the selections: displayvalue(true(),ri!arrayToSearch,ri!replacementArray,null). It is used with doforeach in node outputs of the form where the selection is made (doforeach("rule1",ac!selections,pv!authorLast_text) to save the lastname in the selected row to a new PV, selectedLast; nonselected rows have empty values in selectedLast. Second rule (=ri!input<>"") removes the empty values from selectedLast and is used in a script task following the selection form [filterlist("rule2",pv!selectedLast)]. Even though the first rule says to return null if not found, the empty values are not nulls and need to be removed by filterlist instead of filternulls.

To save someone else too many hours of work, I'm going to record how I finally got this to work. All variables mentioned are multiples. The first rule returns the values for the selections: displayvalue(true(),ri!arrayToSearch,ri!replacementArray,null). It is used with doforeach in node outputs of the form where the selection is made (doforeach("rule1",ac!selections,pv!authorLast_text) to save the lastname in the selected row to a new PV, selectedLast; nonselected rows have empty values in selectedLast. Second rule (=ri!input<>"") removes the empty values from selectedLast and is used in a script task following the selection form [filterlist("rule2",pv!selectedLast)]. Even though the first rule says to return null if not found, the empty values are not nulls and need to be removed by filterlist instead of filternulls.