New column from 2 linked columns that can appear multiple times in the table.

Hi RobPastoor, 

1. do not split your description and tables to separate posts please. You can edit your post if needed
2. do not put your description into code just send is as text

Result

v1 - Simple way

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("lZRNj4MgEIb/i+eaVHH7cdzvQzcbs91b04PbjpFIJQG97K9faiqOgAs9EQI878zwzhwOUZLGSfoQLaKGxZ8fav0uSmBqPUP88nrdU3mq1ApN/P7Un/8wUGsp4revYV900XFxg63Q4XNVUAmIvm95Tx9o1wsCqe3brmIja42e7grZ4peMS2iR1qO4cCoAwXYM6BmEil8UTT1SNwijAuJsmg7vRA/WwqKrcYinCi6Agtw6Dm0Bg2bpDTiyxDja/tZUSmjQk5x3JRLIOS8RP+dQjrDEczFESsNSd53s3I1cp6XQOOJwneky04VzriNZwGNTbBaG++Fmu2CXWQ7V1JXX93afGI2kWWvHXZNlas2xNnbMrnyNgniajGz/K9G9PT1Qs+Xds2Q27ywJsIRvDmpYGvCZgR+SEa+sK9BpKhqWBQ03c1pZw+74Bw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Article number" = _t, Language1 = _t, Value1 = _t, Language2 = _t, Value2 = _t, Language3 = _t, Value3 = _t, Language4 = _t, Value4 = _t]),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(Source, {"Article number"}, "Attribute", "Value"),
    #"Extracted Text Before Delimiter" = Table.TransformColumns(#"Unpivoted Other Columns", {{"Attribute", each Splitter.SplitTextByCharacterTransition((x)=> not List.Contains({x}, {"0".."9"}), {"0".."9"})(_){0} , type text}}),
    #"Pivoted Column" = Table.Pivot(#"Extracted Text Before Delimiter", List.Distinct(#"Extracted Text Before Delimiter"[Attribute]), "Attribute", "Value", each _),
    #"Added Table" = Table.AddColumn(#"Pivoted Column", "Table", each Table.FromColumns({[Language], [Value]}, {"Language", "Val"}), type table),
    #"Removed Columns" = Table.RemoveColumns(#"Added Table",{"Language", "Value"}),
    #"Expanded Table" = Table.ExpandTableColumn(#"Removed Columns", "Table", {"Language", "Val"}),
    #"Added Value" = Table.AddColumn(#"Expanded Table", "Value", each if [Language] = "nl-NL" then [Val] else null, type text),
    #"Filtered Rows" = Table.SelectRows(#"Added Value", each ([Value] <> null)),
    #"Removed Columns1" = Table.RemoveColumns(#"Filtered Rows",{"Language", "Val"})
in
    #"Removed Columns1"

v2 - Elegant

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("lZRNj4MgEIb/i+eaVHH7cdzvQzcbs91b04PbjpFIJQG97K9faiqOgAs9EQI878zwzhwOUZLGSfoQLaKGxZ8fav0uSmBqPUP88nrdU3mq1ApN/P7Un/8wUGsp4revYV900XFxg63Q4XNVUAmIvm95Tx9o1wsCqe3brmIja42e7grZ4peMS2iR1qO4cCoAwXYM6BmEil8UTT1SNwijAuJsmg7vRA/WwqKrcYinCi6Agtw6Dm0Bg2bpDTiyxDja/tZUSmjQk5x3JRLIOS8RP+dQjrDEczFESsNSd53s3I1cp6XQOOJwneky04VzriNZwGNTbBaG++Fmu2CXWQ7V1JXX93afGI2kWWvHXZNlas2xNnbMrnyNgniajGz/K9G9PT1Qs+Xds2Q27ywJsIRvDmpYGvCZgR+SEa+sK9BpKhqWBQ03c1pZw+74Bw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Article number" = _t, Language1 = _t, Value1 = _t, Language2 = _t, Value2 = _t, Language3 = _t, Value3 = _t, Language4 = _t, Value4 = _t]),
    Transform = Table.FromRows(
       List.TransformMany(Table.ToRows(Source),
            each {List.PositionOf(_, "nl-NL")},
            (x,y)=> {x{0}} & List.Transform({y+1}, (a)=> x{a} ) ),
       type table[Article number=text, Value=text] )
in
    Transform

v3 - Just for fun 🙂

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("lZRNj4MgEIb/i+eaVHH7cdzvQzcbs91b04PbjpFIJQG97K9faiqOgAs9EQI878zwzhwOUZLGSfoQLaKGxZ8fav0uSmBqPUP88nrdU3mq1ApN/P7Un/8wUGsp4revYV900XFxg63Q4XNVUAmIvm95Tx9o1wsCqe3brmIja42e7grZ4peMS2iR1qO4cCoAwXYM6BmEil8UTT1SNwijAuJsmg7vRA/WwqKrcYinCi6Agtw6Dm0Bg2bpDTiyxDja/tZUSmjQk5x3JRLIOS8RP+dQjrDEczFESsNSd53s3I1cp6XQOOJwneky04VzriNZwGNTbBaG++Fmu2CXWQ7V1JXX93afGI2kWWvHXZNlas2xNnbMrnyNgniajGz/K9G9PT1Qs+Xds2Q27ywJsIRvDmpYGvCZgR+SEa+sK9BpKhqWBQ03c1pZw+74Bw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Article number" = _t, Language1 = _t, Value1 = _t, Language2 = _t, Value2 = _t, Language3 = _t, Value3 = _t, Language4 = _t, Value4 = _t]),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(Source, {"Article number"}, "Attribute", "Value"),
    #"Extracted Text Before Delimiter" = Table.TransformColumns(#"Unpivoted Other Columns", {{"Attribute", each Splitter.SplitTextByCharacterTransition((x)=> not List.Contains({x}, {"0".."9"}), {"0".."9"})(_){0} , type text}}),
    #"Grouped Rows" = Table.Group(#"Extracted Text Before Delimiter", {"Article number"}, {{"Value", each _{List.PositionOf([Value], "nl-NL")+1}[Value] , type text}})
in
    #"Grouped Rows"