Currently to extract details of a dynamic lookup from the system using the Rest API's we can only take out displayvalue, Id and _self. Is there a way via which I can extract all the information associated with a dynamic lookup.
Like if I had 4 attributes in select clause of the dynamic lookup, can I extract them all using Rest API's. Currently on CA PPM version 14.3
Through REST alone, that is all you can extract at this time. The REST APIs are being worked on for future releases where expanded capability like that may exist - I would advise if it is important to you (or even just seems like a good suggestion) that an Idea is raised with these details so that it can get on the radar of the product owners.
Otherwise as things stand, it would take an additional SOAP request (e.g. XOG) to get this supplemental data when needed.