Refer out of scope expression

Here is my Expression that is trying to refer something out of scope:=iif(Fields!fee_name.Value<>"monthly", StrConv(Replace(Fields!fee_name.Value,"_"," "), VbStrConv.ProperCase), iif(ReportItems("Text58").value > Fields!fee.Value , StrConv(Replace(Fields!fee_name.Value,"_"," "), VbStrConv.ProperCase) &" (" & FormatCurrency(Fields!fee.Value) & ")" , StrConv(Replace(Fields!fee_name.Value,"_"," "), VbStrConv.ProperCase) ))It is giving me an error Error 2 [rsReportItemReference] The Value expression for the text box ‘fee_name’ refers to the report item ‘Text58’. Report item expressions can only refer to other report items within the same grouping scope or a containing grouping scope. Letters in the names of report items must use the correct case.