-- prepare test data
declare @test table (Employee_ID int, Transaction_Date datetime, Job_Code tinyint, Job_Title varchar(8))

insert @test
select 10070, '11/5/2004', 104, 'Staff' union all
select 10070, '5/6/2005', 104, 'Staff' union all
select 10070, '5/20/2005', 108, 'Manager' union all
select 10070, '7/29/2005', 108, 'Manager' union all
select 10070, '9/9/2005', 108, 'Manager' union all
select 10070, '1/1/2006', 121, 'Director' union all
select 10070, '3/1/2006', 121, 'Director'

-- show test data
select * from @test

-- Do the work!
select		t0.*,
		(
			select	case
					when min(transaction_date) is null then dateadd(day, datediff(day, 0, getdate()), 0)
					else min(transaction_date) - 1
				end
			from	@test t1
			where	t1.employee_id = t0.employee_id
				and t1.transaction_date > t0.begindate
				and t1.job_code <> t0.job_code
				and t1.job_title <> t0.job_title
		) enddate
from		(
			select		employee_id,
					min(transaction_date) begindate,
					job_code,
					job_title
			from		@test
			group by	employee_id,
					job_code,
					job_title
		) t0
order by	t0.employee_id,
		t0.begindate