Restrict specific document of record type to direct line manager only

Summary:

We need to lock down a new document of record type so that only a direct line manager can see it. Anyone above the line manager should not have access.

There are additional document types that should remain visible to the entire hierarchy.

The current Line Manager Custom role has a Person Security Profile by Manager Hierarchy without maximum levels in hierarchy being set.

What is the best way to achieve this behaviour?

Would doing the following work?

1. Create new Person Security profile with Maximum Levels in Hierarchy as 1
2. Create new Document Type Security Profile that includes the restricted documents