Compare Column Names from Multiple Sources

Hi gadao, another solution:

You have to define your tables here:

Output:

You can delete steps Table1 - Table4 (they are just as sample tables).

let
    Table1 = #table(Text.ToList("ABCEFH"), {}),
    Table2 = #table(Text.ToList("AHD"), {}),
    Table3 = #table(Text.ToList("HGABD"), {}),
    Table4 = #table(Text.ToList("GAC"), {}),
    DefineTablesHere = [ //I do not know your table names, but you have to specify all of them here.
    Table1 = Table1,
    Table2 = Table2,
    Table3 = Table3,
    Table4 = Table4
  ],
    TablesColNames = List.Transform(Record.ToList(DefineTablesHere), Table.ColumnNames),
    AllColNames = List.Buffer(List.Sort(List.Distinct(List.Combine(TablesColNames)))),
    TableMap = Table.FromColumns(List.Transform(TablesColNames, each List.Transform(AllColNames, (x)=> if List.Contains(_, x) then x else null)), Record.FieldNames(DefineTablesHere))
in
    TableMap