I am trying to migrate a link field field_url from a Drupal 7 site to my Drupal 8 one. The link field is compound, it has a title and a url value. In my process plugin I am selecting the right values (field_url_title and field_url_url), but I don't know how to map them in my yaml definition file. What I have:
field_url: field_url_url field_url_title: field_url_title
...maps correctly the url, but does not populate the title one. What's the destination field machine name I would need to use to add in the link title?