Power Query - formatting - Adding Intermediate "summary" text row

Question

I am transforming some data from a database, and at the end of one of the step, I need to reformat it for sending it as a document to a client. the usual template for this document has intermediate row with a sort of summary of one of the column (just text, no numbers). It would means going from first to second table here under. Is it possible ?

value 1	value metadata1	value's metadata 2	grouping
First	1st M1	1st M2	group 1
Second	2nd M1	2nd M2	group 2
Third	3rd M1	3rd M2	group 3
Fourth	4th M1	4th M2	group 1

value 1	value metadata1	value's metadata 2
group 1
First	1st M1	1st M2
Fourth	4th M1	4th M2
group2
Second	2nd M1	2nd M2
group 3
Third	3rd M1	3rd M2

Answer 1

In powerquery, try below

It groups on grouping and copies that into a new row in value 1 column before expanding

let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
#"Grouped Rows" = Table.Group(Source, {"grouping"}, {{"data", each #table( {"value 1"}, {{_[grouping]{0}}}) & _, type table }}),
ColumnsToExpand = List.RemoveLastN(List.Distinct(List.Combine(List.Transform(Table.Column(#"Grouped Rows", "data"), each if _ is table then Table.ColumnNames(_) else {}))),1),
#"Expanded data" = Table.ExpandTableColumn(#"Grouped Rows", "data",ColumnsToExpand ,ColumnsToExpand ),
#"Removed Columns" = Table.RemoveColumns(#"Expanded data",{"grouping"})
in  #"Removed Columns"