The client requested the creation of a new field for the web content that allows overwriting the createDate value when filled. This new field references manual_datetime. The question is: in the blueprint sort configuration, is it possible to apply a logic that considers both fields, giving priority to manual_datetime when it is filled, and otherwise using the conventional createDate?
Yes, this should be possible. You can define multiple fields, and the order determines which one applies first. Refer to https://learn.liferay.com/w/dxp/search/liferay-enterprise-search/search-blueprints/search-blueprints-configuration-reference#sort-configuration and to https://www.elastic.co/guide/en/elasticsearch/reference/8.19/sort-search-results.html for helpers.