If anyone cares to know, I figured this out.
Current
=IIF(DateDiff("d",Fields!Document_Date.Value, Now())<=30, Fields!Current_Trx_Amount.Value, "")
31-60 days
=iif(DateDiff("d",Fields!Document_Date.Value,now())>=31 and DateDiff("d",Fields!Document_Date.Value,Now())<=60,Fields!Current_Trx_Amount.Value,"")
61-90 days
=iif(DateDiff("d",Fields!Document_Date.Value,now())>=61 and DateDiff("d",Fields!Document_Date.Value,Now())<=90,Fields!Current_Trx_Amount.Value,"")
91-120 days
=iif(DateDiff("d",Fields!Document_Date.Value,now())>=91 and DateDiff("d",Fields!Document_Date.Value,Now())<=120,Fields!Current_Trx_Amount.Value,"")
121-150 days
=iif(DateDiff("d",Fields!Document_Date.Value,now())>=121 and DateDiff("d",Fields!Document_Date.Value,Now())<=150,Fields!Current_Trx_Amount.Value,"")
151+ days
=IIF(DateDiff("d",Fields!Document_Date.Value, Now())>=151, Fields!Current_Trx_Amount.Value, "")
If you correlate this with the screenshots it will make sense on how to apply it to your situation.
