Create a field for Line Manager in a new request

Create a field for Line Manager in a new request

Hi - apologies if this has been asked, but I can't find the answer!! I am trying to create a field for Line Manager for a new joiner type of service request. To ensure it is correct, I was hoping that I could make the field query the list of requestors within ServiceDesk plus, which sync's from our AD, but can't seem to figure out how to do it. Any ideas?  Thanks!

                  New to ADSelfService Plus?