Help merging rows based on Time Constraints!

No problem. This is probably intermediate-level Power Query so I'll try and explain the steps in as much detail as possible.

First, copy this code, create a new blank query in PQ, open Advanced Editor an paste it over everything in that window. You'll then be able to follow each step:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("ndCxCoMwEIDhV5HMgpe7S9JkdSoU7C4OItJKQUHt+zeFdkhpQ9IpCeE+fq5txXlct2UupCgFSiQCaaz1D5IVqAoB0T9AOzD+bNZLP09bv0+vkfo6Dreiue/+flqG90dXpsLKsf0NH+c/XSSnIsGhi1EXvKsTez8WEcDPcVasLVvF5ssiSKYGU7or0cEhOTgHpigcBnOGq3OCPdw9AA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Name = _t, ID = _t, Date = _t, Time = _t, #"Person Group" = _t, Status = _t, #"Attendance Check Point" = _t]),
    chgTypes = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Time", type time}}),
    addDateTime = Table.AddColumn(chgTypes, "dateTime", each [Date] & [Time], type datetime),
    sort_ID_dateTime = Table.Sort(addDateTime,{{"ID", Order.Ascending}, {"dateTime", Order.Ascending}}),
    addIndex1 = Table.AddIndexColumn(sort_ID_dateTime, "Index1", 1, 1, Int64.Type),
    addIndex0 = Table.AddIndexColumn(addIndex1, "Index0", 0, 1, Int64.Type),
    mergeIndex1Index0 = Table.NestedJoin(addIndex0, {"ID", "Index1"}, addIndex0, {"ID", "Index0"}, "addIndex0", JoinKind.LeftOuter),
    expandIndex1Index0 = Table.ExpandTableColumn(mergeIndex1Index0, "addIndex0", {"dateTime"}, {"addIndex0.dateTime"}),
    filterCheckOutRows = Table.SelectRows(expandIndex1Index0, each ([Status] = "Check In")),
    remOthCols = Table.SelectColumns(filterCheckOutRows,{"Name", "ID", "Person Group", "Attendance Check Point", "dateTime", "addIndex0.dateTime"}),
    addTimeWorked = Table.AddColumn(remOthCols, "timeWorked", each [addIndex0.dateTime] - [dateTime])
in
    addTimeWorked

1) Merge [Date] and [Time] columns into [dateTime] column. This isn't entirely necessary, but makes some subsequent steps a bit simpler.

2) Sort the table by [ID], [dateTime] ascending. This is key to ensure the entries by person are sequential/chronological.

3) Add two index columns, one starting from 1, the other from 0. These are basically new key columns, offset by one, to allow us to merge the table on itself to put the next row values alongside the previous row values.

4) Merge the table on itself on [ID], [Index1] = [ID], [Index0]. This matches the next row for the same person to ensure we on't mix up two people's records.

5) Expand the [dateTime] column from the merged column. This gets us the next [dateTime] value on the current row.

6) Filter out any rows that show "Check Out". We now have the Check Out times on our Check In rows, so we don't need these any more.

7) Remove other columns - just to tidy up a bit.

8 ) Add a [timeWorked] column which is just the difference between our new [dateTime] column an the original.

Overall, this gives the following output:

Pete