Try this:
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("nZJNCsQgDEbv4rrQ/Fq77n4uUHr/a1QHBqZiUlUQs8gjz4+cZ2BACEvYfyfXuuK2EpDkGvM9Pkd5vn0pXMsrRDMQV5D+Q4kYFQRgRM+CXD0LcvU60qOZ9PohrqAqPd0RRGREz4JcPQty9V7SKwO19G0D6Y1BXEHx8SdJAoxo7F57kgW5ehbk6nWkF2fS64e4gp7pJY2oBMbutSdZkKtnQQ296wY=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Plant = _t, Confirmation = _t, #"Posting Date" = _t, Shift = _t, Workcenter = _t, #"Single Capacity Name" = _t, #"Opening Time" = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{
{"Plant", Int64.Type}, {"Confirmation", Int64.Type}, {"Posting Date", type date}, {"Shift", Int64.Type},
{"Workcenter", type text}, {"Single Capacity Name", Int64.Type}, {"Opening Time", Int64.Type}}),
//Add index column to enable re-sorting of results
#"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1, Int64.Type),
#"Grouped Rows" = Table.Group(#"Added Index", {"Confirmation", "Posting Date", "Workcenter"}, {
{"all", each _,
type table [Plant=nullable number, Confirmation=nullable number, Posting Date=nullable date,
Shift=nullable number, Workcenter=nullable text, Single Capacity Name=nullable number,
Opening Time=nullable number, Index=Int64.Type]},
{"Added Value", each List.Sum([Opening Time]), type nullable number}}),
#"Expanded all" = Table.ExpandTableColumn(#"Grouped Rows", "all",
{"Plant", "Shift", "Single Capacity Name", "Opening Time", "Index"}),
//sort back to original order
#"Sorted Rows" = Table.Sort(#"Expanded all",{{"Index", Order.Ascending}}),
//Remove index column and re-arrange the columns
#"Reordered Columns" = Table.ReorderColumns(#"Sorted Rows",
Table.ColumnNames(#"Added Index")),
#"Removed Columns" = Table.RemoveColumns(#"Sorted Rows",{"Index"})
in
#"Removed Columns"
