Reconciliation

Hi, I've played with this a while and I can provide possible combinations of Finacial Transactions for each Bank Transactions (I know that assignment was different)

Output

let
    BankTransactions = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcjJU0lEyNFCK1QGyjYBsEyjbGMg2g7JNkNimIPUmSrGxAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Value = _t]),
    FinancialTransactions = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcjNU0lEyNFCK1QGyjYBsYyjbGMg2hTBNEExTJNVmILYRlGMO5JgoxcYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Value = _t]),
    BTChangedType = Table.TransformColumnTypes(BankTransactions,{{"Value", type number}}),
    FTChangedType = Table.TransformColumnTypes(FinancialTransactions,{{"Value", type number}}),
    FTBufferedIDList = List.Buffer(FTChangedType[ID]),
    Ad_FTCombinations = Table.AddColumn(FTChangedType, "Combinations", each 
        [ a = List.PositionOf(FTBufferedIDList, [ID]),
          b = List.Buffer(List.RemoveRange(FTBufferedIDList, 0, a+1)), //list for current row combinations
          c = List.Count(b),
          d = List.Accumulate({1..c}, {[ID]}, (state, current)=> state &
                    List.Transform({0..c-1}, (y)=> 
                            [ d1 = List.Range(b, y, current),
                              d2 = if List.Count(d1) < current then null else Text.Combine({[ID]} & d1, "+")
                            ][d2]) ),
          e = if b = {} then {[ID]} else List.RemoveNulls(d) 
        ][e], type list),
    AllCombinations = Table.FromList(List.Combine(Ad_FTCombinations[Combinations]), (x)=> {x}, type table[ID=text]),
    Ad_Value = Table.AddColumn(AllCombinations, "Value", each 
        [ a = Text.Split([ID], "+"),
          b = List.Transform(a, (x)=> List.First(Table.SelectRows(FTChangedType, (y)=> y[ID] = x)[Value])),
          c = List.Sum(b)
        ][c], type text),
    Filtered = Table.SelectRows(Ad_Value, each [Value] <= List.Max(BTChangedType[Value])),
    BufferedCombinations = Table.Buffer(Filtered),
    StepBackToBankTransactions = BTChangedType,
    Ad_Combinations = Table.AddColumn(StepBackToBankTransactions, "Combinations", each BufferedCombinations, type table),
    AddedCustom = Table.AddColumn(Ad_Combinations, "Custom", each Table.SelectRows([Combinations], (x)=> x[Value] = [Value])),
    ExpandedCustom = Table.ExpandTableColumn(AddedCustom, "Custom", {"ID"}, {"Possible Combinations"}),
    RemovedColumns = Table.RemoveColumns(ExpandedCustom,{"Combinations"})
in
    RemovedColumns