Add options that your practice can use to categorise documents by what type of document it is. For example, Correspondence or Legal.
When configuring the type settings, you see subtypes in a hierarchical structure. But when a user selects a type for a document they're uploading, the document type and subtype are displayed together.
When you add a document to the Documents page, they can choose from either the document type or document type and subtype together. For example, Correspondence or Correspondence > Legal.