Install Equi Join.
The Equi Join module allows you to create relationships between
different entities based on an arbitrary field. This allows the use of
relationships in Views without having to add Node References to a
content type, which may not be an option when displaying data stored
on a third-party database or data provided through custom Views
handlers. That said, it works with nodes as well.
I must confess, I have never used this module before now, so my method of getting it to work was by trial and error. Here goes:
In your view, add a relationship
Equi Join: Content, and configure both
left field and
right field to be on field 'ID' (I am assuming you re-used the ID field for both Employee A and Employee B. If not, adjust as appropriate). Make sure to provide a unique Identifier (will be used later to identify the relationship).
Add all the fields from Employee A and Employee B. For each of the fields of Employee B, make sure to add the relationship of the equi join.
Add Filter Criteria for each of the fields (AND). For all of them, Operator must be
Is not empty (NOT NULL). For each of the Filter Criteria using fields on Employee B make sure to add the relationship of the equi join. If you have a required field on any of the Employee Types, then adding just that one required field would be sufficient for that Employee Type. If none of the fields are required, then you might end up filtering out a legitimate row with empty values. So best if each employee type has at least one required field on it.