Can you further elaborate on your issue? What exact criteria did you do your search for?
I'm in a school where sometimes a teacher might have their own child in a class. So for conference notes, a teacher should be able to see all fields of all children except their own child.
I have an individual privilege set for each teacher that has a child at the school. It's set to view only layouts and value list, scripts are executable only and records view is set to limited, depending on the last name of the child, name last ≠ "smith" . They can edit and see all fields.
This works. Teachers can edit conference notes for all the other children. When they come to their son/daughter's record, the fields say <No Access>. When the teachers try to do a find by any field they get 'No records match this set of find requests.'