hide a view field content for anonymous only? How can I hide a field for the anonymous user in a view?

Logged in users should still be able to see the field.

(Drupal 8.3.0)
This might be overkill for just one field, but you could take a look at the Field Permissions module: https://www.drupal.org/project/field_permissions. This module allows you to set permissions on a per-field basis, so you can just remove all permissions for anonymous users for this field.