Holdings - hierarchical facet by permanent locations

Purpose/Overview:
Each location consists out of hierarchical data that includes: institution, campuses, libraries and locations. Each location has a code and a name. When creating the facets for the permanent location we need to take into consideration that in large institutions (consortia, for example) there might be hundreds of locations and the user might be interested only in locations associated with just one library.

Requirements/Scope:
1. Holdings search based on the holdings.permanentLocationId
2. Facet should be on two levels:

• Library as level 1 ( "name" and "code" elements)

• Location as level 2 ("name and "code" elements)

Approach:

Acceptance criteria:

• Search returns accurate hit count

• Search returns instances with holdings that matches specified permanent location

• User can narrow down from library to location

• User can limit instances search by location data associated with items or holdings

Current CQL query example:
(holdingsRecords.permanentLocationId=="fcd64ce1-6995-48f0-840e-89ffa2288371") sortby title
matches: instances that have holdings associated with Main Library location

Additional information:
The request GET /location-units/libraries returns

Request GET /locations returns: