I am trying to create alternative registration forms and include fields from the profile entity form. The profile module only allows to add all fields to the registration, it attaches the whole profile, not single fields.

My goal is to be able to create multiple registration pages, for marketing purposes, each beeing different and consisting of different fields from the user account and from profile, e.g.:

Page1: email + password + birthday (profile field) Page2: eamil + birthday (profile field) + preferences (profile field) Page3: email + position (user field) + preferences (profile field) …

How can I do this? I thought of the following possibilities:

a) creating different forms extending RegisterForm and than removing fields I don’t want and add fields from profile. However I don’t know how to add fiels from profile b) create different form displays and use hook_form_user_register_form_alter to add the fields from profile, but as a) I don’t know how