Marriage of 2 Collections

Dear Experts,

See following code...........

Code:

[Collection: MinMaxStockItem]
        Type            : Stock Item
        Child of        : #StockGrpName

[Collection : VouchersColl]
    Type        : Voucher

[Collection: SummaryColl]
    Source Collection     : MinMaxStockItem
    Walk            : Inventory Entries
    By            : StockItemName        : $StockItemName
    Aggr Compute        : OutStkTotalQty    : Sum    : IF @@OnlySaleCN Then $BilledQty     Else ""

My repeat uses Collection:MinMaxStockItem. The Value computed is in Collection:SummaryColl.

How to arrange their marriage? So i can avail of the computed values in Collection:MinMaxStockItem.

 

I also tried using Formula and Object:Ledgers ......... but not picking up........

I have group-wise StockItem report.............