Hi @NBeheydt ,
Firstly you shouldn't be creating Entity record directly as per best practice, it should come using Entity types or Entity class. That way you don't really need to worry about "Applies to record" field as it's a mandatory field at the entity record level.
Let's understand how,
Now, you consider Entity type as "Facilities", it has Entity filter on "Location" table:
Now, if you take one of the entity from this entity type, the applies to field autopopulates and greyed out:
