Transpose/Transform Multiple Rows into Single Row

you should be able to adjust this code

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WSlTSUTJUitWJVkqCs5LhrBQ4KxXIMgKz0uCsdCDLGMzKALJMwKxMIMsUzMqCs7LhrBwIKxYA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [name = _t, id = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"name", type text}, {"id", Int64.Type}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"id"}, {{"names", each Table.Transpose(Table.FromList(List.Combine({[name]}))), type table}}),
    #"Expanded names" = Table.ExpandTableColumn(#"Grouped Rows", "names", {"Column1", "Column2", "Column3", "Column4"}, {"Column1", "Column2", "Column3", "Column4"})
in
    #"Expanded names"

you should:

1) replace the red code with your table definition

2) add coma at the end of your table definition

3) replace blue step name with whatever is the the name of the last step in your table definition

hope that helps :)

if you replace last row in the sytnax with this

= Table.ExpandTableColumn(#"Grouped Rows", "names", List.Distinct(List.Combine(List.Transform(#"Grouped Rows"[names], each Table.ColumnNames(_)))), List.Distinct(List.Combine(List.Transform(#"Grouped Rows"[names], each Table.ColumnNames(_)))))

then it will always expand all the columns

try this

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("Tcw5DsAgEEPRu0xNCrKcBlGQQDbI/dtYM5Khe/qWHIIkceIlOmjy9N411IPKVIFm1Uld0KK6oVX1QJtJH80vlbqGvVKN+kzxBw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [name = _t, id = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"name", type text}, {"id", Int64.Type}}),
    ExcludedItems = Table.SelectRows(#"Changed Type", each Text.EndsWith([name], "-1")),
    ExcludedItemsWithKey = Table.AddColumn(ExcludedItems, "Custom", each Text.Start([name], Text.Length([name]) - 2)),
    WithoutExcludedItems = Table.SelectRows(#"Changed Type", each not Text.EndsWith([name], "-1")),
    #"Merged Queries" = Table.NestedJoin(WithoutExcludedItems,{"name", "id"},ExcludedItemsWithKey,{"Custom", "id"},"WithoutExcludedItems",JoinKind.LeftOuter),
    #"Expanded WithoutExcludedItems" = Table.ExpandTableColumn(#"Merged Queries", "WithoutExcludedItems", {"name"}, {"name with -1"})
in
    #"Expanded WithoutExcludedItems"