Display unfiltered data

...                                        }),

To make the 2nd filter optional, we modified that to:
                                                  if(and(not(isnull(local!salesMonth)),local!salesMonth<>""),
                                                  'logicalExpression|filter|search':'type!{www.appian.com/.../2009}LogicalExpression'(
                                                  operator:"AND",
'logicalExpression|filter|search':{'type!{www.appian.com/.../2009}QueryFilter'(field: "requestStatus", operator: "<>", value:cons!SALES_CANCELLED),
                                                  'type!{www.appian.com/.../2009}QueryFilter'(field: "soldMonthYear_txt", operator: "=", value:local!salesMonth),
                                                  'type!{www.appian.com/.../2009}QueryFilter'(field: "soldDate_date", operator: "between", value:{rule!SALES_Get_Date(),today()+1})
                                                  }),
                                                  'logicalExpression|filter|search':'type!{www.appian.com/.../2009}LogicalExpression'(
                                                  operator:"AND",
'logicalExpression|filter|search':{'type!{www.appian.com/.../2009}QueryFilter'(field: "reques...

...tStatus", operator: "<>", value:cons!SALES_CANCELLED),
                                                  'type!{www.appian.com/.../2009}QueryFilter'(field: "soldMonthYear_txt", operator: "<>", value:""),
                                                  'type!{www.appian.com/.../2009}QueryFilter'(field: "soldDate_date", operator: "between", value:{rule!SALES_Get_Date(),today()+1})
                                                  })
                                                  ),
But we get error "A function expression contains duplicate keywords. Keyword: logicalExpression|filter|search. " Can you help with the proper way to implement conditional filters.

Any links to Documentation which provides the syntax? (I couldn't find one)