This Extra Field Type is available in Profile Builder 2.0, Hobbyist or Pro.
You can use this extra field type to allow users to choose their User Role.
You can specify the field title, meta-name to be stored in the database, description and what roles to be displayed in the form. You can drag and drop the roles to rearrange them.
Also, you can set whether this field should be required or not.
This is how it looks like in the front-end.