Probably there is a neater solution.
Until someone provides it, you can try with steps below.
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("pdA9C4MwEIDhv1Iyi1y+beaObZcKHcRB0FYXC1UH/30tMSbGQJFClnsJD9xlGcI0BhETIPhAiOJcAUbRqlLF5nptnnXf1c2jn4bb0JbFuPr7HQhlHOVR5hEA0/sXFhpmCwHYwk4lS13Bl5eBmQfLDcyCMN8LJxtYhGBs9zgV42/26LMOgBNb6S6Wg2a5BZiihnWqPcO56CvjpkPVzTD3YKxhESLcKoPwvSrbhRYeTTQtg6eQ7iaBU6T18Daw9GCK8vwD", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [DatetimeStart = _t, DatetimeFinish = _t, #"Shift " = _t, Weekday = _t, Mastercalendar = _t, ORDERID = _t]),
Removed = Table.RemoveColumns(Source,{"Shift ", "Weekday", "Mastercalendar"}),
Locale = Table.TransformColumnTypes(Removed, {{"DatetimeStart", type datetime},{"DatetimeFinish", type datetime}}, "hr-HR"),
AddedHrs = Table.TransformColumns(Locale,{{"DatetimeStart", each _ + #duration(0,2,0,0), type datetime}, {"DatetimeFinish", each _ + #duration(0,2,0,0), type datetime}}),
ShiftCol = Table.AddColumn(AddedHrs, "Shift", each if [DatetimeStart]>= DateTime.From(Date.From([DatetimeStart])) and [DatetimeStart]< DateTime.From(Date.From([DatetimeStart])) + #duration(0,8,0,0)
then "Nifghtshift"
else if [DatetimeStart]>= DateTime.From(Date.From([DatetimeStart])+ #duration(0,8,0,0)) and [DatetimeStart]< DateTime.From(Date.From([DatetimeStart])) + #duration(0,16,0,0)
then "Dayshift"
else "Latehift"),
WeekdayCol = Table.AddColumn(ShiftCol, "Weekday", each Date.DayOfWeekName([DatetimeStart])),
#"Added Custom" = Table.AddColumn(WeekdayCol, "Mastercalendar", each Date.From([DatetimeStart]), type date),
Reset = Table.TransformColumns(#"Added Custom",{{"DatetimeStart", each _ - #duration(0,2,0,0), type datetime}, {"DatetimeFinish", each _ - #duration(0,2,0,0), type datetime}}),
FINAL = Table.ReorderColumns(Reset,{"DatetimeStart", "DatetimeFinish", "Shift", "Weekday", "Mastercalendar", "ORDERID"})
in
FINAL
