How can an employee attend a meeting before they are an employee? Well, if using vs. 11 you can use your existing primary relationship (in your case using names). Just filter the portal by calculation of: Table2::LectureDate ≥ Table1::StartDate
If prior version then you will need to create another table occurrence of Table2 and join them as:
Table1::EmployeeName = Table2::NameOfEmployeeInAttendance
Table1::StartDate ≤ Table2::LectureDate
... and then place that portal on your layout.
UPDATE: I forgot the most important part ... you should be joining all of your tables based upon keys and not names. In your case, the UniqueID you reference in table 1 should be as foreign key in table 2 and relationship based upon keys. :smileyhappy: