BILL_ID / ... / BILL_ON    
1      ...        - (общий счет)    
-      ...        1 (текущий счет, списанный на общий)    
-      ...        1    
-      ...        1    
2      ...        -    
-      ...        2    
-      ...        2    
-      ...        2

SELECT Bill_charge.BILL_ID, Bill_charge.OperID, Bill_charge.[Реф №], 
Bill_charge.Дата1, null as Дата2, Bill_charge.Наименование, Bill_charge.Эквивалент1, Bill_charge.BILL_ON
FROM Bill_charge
where bill_charge.bill_id is not null
UNION ALL SELECT Bank.BILL_ID, Bank.OperID, Bank.[Реф №],null,  Bank.Дата2, 
Bank.Наименование, Bank.Эквивалент1, Bank.BILL_ON
FROM Bank
where bank.bill_on is not null;

SELECT b.BILL_ID, b.OperID,[Реф №], b.Дата1, b.Наименование, b.Эквивалент1, null as   Эквивалент2, 
null as bill_id, b.BILL_ON,  1  as a, 
IIf(b.[bill_id] Is not  Null,b.[BILL_ID],b.[Реф №]) as numb
FROM ПАРТНЕРЫ_Report_1_recordsource as b

WHERE ((([b.bill_id] Is Null And [b.bill_on] Is Null)=False) And 
((IIf([b.bill_id] Is Not Null,b.[дата1]>=[forms]![партнеры_договор_поставщики]![fld_DateS2] And 
b.дата1<[forms]![партнеры_договор_поставщики]![fld_DatePo2],True))<>False) And 
((IIf([b.bill_on] Is Not Null,b.[дата2]>=[forms]![партнеры_договор_поставщики]![fld_Dates2] And 
b.дата2<[forms]![партнеры_договор_поставщики]![fld_DatePo2],True))<>False))

ORDER BY IIf(IsNull(b.[bill_on]),b.[bill_id],b.[bill_on]), IIf(IsNull(b.[bill_on]), 0 , 1 )

UNION ALL SELECT null, d.OperID , d.[Реф №] , d.Дата2 , d.Наименование , 
null,d.Эквивалент2 , d.REF_ON , null,  0  as a, IIf(d.[bill_id] Is Not Null,d.[BILL_ID],d.[Реф №]) as numb
FROM Bank as d

where (d.[реф №] = [forms]![партнеры_договор_поставщики]![fld_ref]) and
 (d.эквивалент1 is null) and (d.[дата2]>=[forms]![партнеры_договор_поставщики]![fld_Dates2] And 
d.дата2<[forms]![партнеры_договор_поставщики]![fld_DatePo2])
ORDER BY a;

SELECT Bill_charge.BILL_ID as a, Bill_charge.OperID, Bill_charge.[Реф №], Bill_charge.Дата1, null as Дата2,
Bill_charge.Наименование, Bill_charge.Эквивалент1, Bill_charge.BILL_ON as b
FROM Bill_charge
where bill_charge.bill_id is not null
UNION ALL SELECT Bank.BILL_ID as a, Bank.OperID, Bank.[Реф №],null, 
 Bank.Дата2, Bank.Наименование, Bank.Эквивалент1, Bank.BILL_ON as b
FROM Bank
where bank.bill_on is not null
ORDER BY IIf(IsNull(b),a,b), IIf(IsNull(a), 0 , 1 )