Search API: where I can specify "motivation" property?

[daynewss]

If I want to search only for some type of motivation, where I can set url property? Actually, where I can set any property, like date, motivation, user? If I want to perform one search in paintings and another in commenting, and another in describing where can I set these parameters? Example from iiif search API

http://example.org/services/manifest/search?q=bird&motivation=painting