Count if formula for multiple columns in power query

markfikry 

You may modify it as

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    countif = Table.AddColumn(
        Source, "count",
        each List.Count( List.Select(
                { [H4], [H5], [H6], [H7], [H8]  } /*Record.FieldValues(_)*/,
                each _ <=15 ) ) )
in
    countif

defining fields directly.