This is one way.
In the formula bar, type this below (you may need to replace Source with the name of your previous step):
= Table.TransformColumns(Source,{"Value.B", each Record.FieldValues(_)})
and press enter to get this:

Then, click the button at the top of the Value.B column to extract values and click Extract Values...
Then select --Custom-- in the dropdown and type ( and click OK to get this:

Then click Transform, Format, Add Suffix and type ) and click OK to get this:

Then click Transform, Group By and set it up like this:

and click OK to get this:

Then click Add Column, Custom Column and set it up like this:

and click OK to get this:

Then you can remove the AllData column and move the Value.B column to get this:

Here's my M code:
let
Source = Table,
#"Got Field Values" = Table.TransformColumns(Source,{"Value.B", each Record.FieldValues(_)}),
#"Extracted Values" = Table.TransformColumns(#"Got Field Values", {"Value.B", each Text.Combine(List.Transform(_, Text.From), "("), type text}),
#"Added Suffix" = Table.TransformColumns(#"Extracted Values", {{"Value.B", each _ & ")", type text}}),
#"Grouped Rows" = Table.Group(#"Added Suffix", {"Name", "Value.A", "Value.E"}, {{"AllData", each _, type table [Name=text, Value.A=text, Value.B=text, Value.E=text]}}),
#"Added Value.B" = Table.AddColumn(#"Grouped Rows", "Value.B", each [AllData][Value.B]{0}&"#(lf)"&[AllData][Value.B]{1}),
#"Removed Columns" = Table.RemoveColumns(#"Added Value.B",{"AllData"}),
#"Reordered Columns" = Table.ReorderColumns(#"Removed Columns",{"Name", "Value.A", "Value.B", "Value.E"})
in
#"Reordered Columns"