MS Access how to show only vacancies?

Question

Microsoft Access

There is a table with positions. In it, many positions are repeated, but they have different id.
There is a table with workers.
How to make it so that when choosing an employee a position, then it would not be possible to assign the same to another?
Or rather, when choosing the next one, it was not even visible that this position existed, only vacancies

Answer 1

you can see the presence of this position, only vacancies

Filter: Position has no employee.