The settings for Schema Local Business Multiple Departments are found under Schema → Departments.
If your Local Business has multiple departments with different locations, you can enable Multiple Departments within the Local Business extension settings.

Once you save settings, you will have a new post type called “schema-departments” for Departments.

This new Departments post type will allow you to insert multiple departments and locations details to have them added to your main local business structured data markup.

You can add unlimited number of departments. See, example below:

You can enter department details and customize it the way you like, and have it added to your Local Business structured data.