Try:
SELECT T0.[RefDate], T2.[AcctName], T1.[Project], T0.[Ref1], T0.[Ref2], T1.[Debit], T1.[Credit] FROM [dbo].[OJDT] T0 INNER JOIN [dbo].[JDT1] T1 ON T0.TransId = T1.TransId INNER JOIN OACT T2 ON T1.Account = T2.AcctCode WHERE T0.refdate between [%1] and [%2] and T2.[GroupMask] = 1