In order to obtain the LuciadFusion Studio REST API resource corresponding to a Service or Dataset CSW record, look for a related resource link in the record that points to the /api/data/{id} or /api/services/{id} REST API endpoint. The link will have the protocol set to LUCIAD:FUSION:STUDIO-1.0-http-rest-get.

Note that you need to set the ElementSetName to full in your CSW request in order to have related resource links be included in the records of the CSW query result.