When mapping a reference field you need to drill down and select fields. You can choose 2 fields or even more to set the reference. However, up till now when mapping the reference field we only showed the first field you mapped to, without displaying the names of the other fields in the chain. A user by the name of Netta (from JFrog) found this unclear and so we decided to fix it and display all of the fields you selected under the ‘Reference’ button. Thank you, Netta! :-)
FYI, this was updated in the Get mapping modal as well as inside the Lookup mapping modal.
For example:
while mapping fields to the SF Contact object (like you can see in the first line in the image: 'Contact name' -> 'Full name' field), you can also
map a reference field and display information from the related Account object. (like you can see in the second line: Account ID -> Account Name).
So, as you can see, the first selected field in the reference (Account ID) is displayed in the dropdown, and as of now the Name field is also displayed - under the 'Reference' button.
Enjoy!