Power-Query - Foreach or any other

I think that you may be overcomplicating this one. You should just need your first table:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCgtX0lGqgONYnWilgPyi4oxUJGGwqE9iSiKIDUYQhUGpeYmlOSUwIZDCWAA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [Car = _t, Deutschland = _t, Frankreich = _t, Russland = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Car", type text}, {"Deutschland", type text}, {"Frankreich", type text}, {"Russland", type text}}),
    #"Unpivoted Columns" = Table.UnpivotOtherColumns(#"Changed Type", {"Car"}, "Attribute", "Value"),
    #"Filtered Rows" = Table.SelectRows(#"Unpivoted Columns", each ([Value] = "x")),
    #"Removed Columns" = Table.RemoveColumns(#"Filtered Rows",{"Value"}),
    #"Renamed Columns" = Table.RenameColumns(#"Removed Columns",{{"Attribute", "Country"}})
in
    #"Renamed Columns"