I followed the steps on skvare to index CiviCRM contacts via Search API, then to have Views list the contacts with the search box as an exposed filter.
I need to expose a filter that filters results based on what membership type the contact has. That might require a relationship, which is currently not an option in Views for me, so I might have to write a custom relationship handler as well as the custom filter handler. I have been trying to find the code to read to use as a guide but I have been unable to figure out whether these handlers are being defined in CiviCRM, Views, Search API, or the Civicrm Entity module which I'm also using.
How do you define a custom relationship and filter handlers for custom fields on CiviCRM contacts being displayed via Search API, CiviCRM Entity, and Views?