Not really knowing the structure of your keys - something like this should work.
SELECT
s.PI,
s.JobID,
s.FormID,
s.ShiftID,
s.StartEvent,
s.SW,
s.SG,
e.EndEvent,
e.EG,
e.EW
FROM
[BaseTable] s
INNER JOIN
[BaseTable] e
ON (s.PI = e.PI AND
s.JobId = e.JobId AND
s.FormId = e.FormId AND
s.ShiftId = e.ShiftId AND
e.EndEvent = (SELECT
MAX(EndEvent)
FROM
[BaseTable]
WHERE
s.PI = PI AND
s.JobId = JobId AND
s.FormId = FormId AND
s.ShiftId = ShiftId))
WHERE
s.StartEvent = (SELECT
MIN(StartEvent)
FROM
[BaseTable]
WHERE
s.PI = PI AND
s.JobId = JobId AND
s.FormId = FormId AND
s.ShiftId = ShiftId)
