PQ - Grouping columns in rows and get data marked by x together

[sandy666]

We have a source table where the first column is data and the second is a selection column with an x marker (and so it is with each subsequent column: data column and marker column). What we want to achieve is to group the columns without the marker columns and get the data for the corresponding columns separated by commas.

see example:

source table

A	A.X	B	B.X	C	C.X	D	D.X
Bob		Sara		Ford	x	item01
Joe	x	Mary	x	Fiat		item02	x
Dean		Cathy		Porsche	x	item03
Mark				GMC	x	item04	x
Sergio	x					item05

expected result:

Group	Result
A	Joe, Sergio
B	Mary
C	Ford, Porsche, GMC
D	item02, item04

// Query1
let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    Text = Table.TransformColumnTypes(Source,{{"A", type text}, {"A.X", type text}, {"B", type text}, {"B.X", type text}, {"C", type text}, {"C.X", type text}, {"D", type text}, {"D.X", type text}}),
    MC1 = Table.CombineColumns(Text,{"A", "A.X"},Combiner.CombineTextByDelimiter("#", QuoteStyle.None),"A"),
    MC2 = Table.CombineColumns(MC1,{"B", "B.X"},Combiner.CombineTextByDelimiter("#", QuoteStyle.None),"B"),
    MC3 = Table.CombineColumns(MC2,{"C", "C.X"},Combiner.CombineTextByDelimiter("#", QuoteStyle.None),"C"),
    MC4 = Table.CombineColumns(MC3,{"D", "D.X"},Combiner.CombineTextByDelimiter("#", QuoteStyle.None),"D"),
    UOC = Table.UnpivotOtherColumns(Table.Transpose(Table.DemoteHeaders(MC4)), {"Column1"}, "Attribute", "Value"),
    Trim = Table.AddColumn(Table.SelectRows(UOC, each Text.Contains([Value], "#x")), "Result", each Text.Trim(Text.TrimEnd([Value],"x"),"#")),
    TB = Table.TransformColumns(Table.SelectColumns(Trim,{"Column1", "Result"}), {{"Column1", each Text.BeforeDelimiter(_, "."), type text}}),
    List = Table.AddColumn(Table.Group(TB, {"Column1"}, {{"Count", each _, type table [Column1=text, Result=text]}}), "Result", each [Count][Result]),
    Result = Table.RenameColumns(Table.TransformColumns(List, {"Result", each Text.Combine(List.Transform(_, Text.From), ", "), type text}),{{"Column1", "Group"}})
in
    Result

Group	Result
A	Joe, Sergio
B	Mary
C	Ford, Porsche, GMC
D	item02, item04