Allow data source filtering by directory structure

Provide capability for filtering data sources by their directory structure. For example, if there are many directories containing similar compartment data, a user will be able to filter these directories to a subset using understandable function arguments.

The issue does not name an implementation file, entry point, or test. First inspect the repository's data-source loading and filtering APIs, then determine how directory structure should be represented in function arguments. Done means users can select a subset of directories containing similar compartment data, with tests covering the filtering behavior.

Written by the indexing model from the issue text.