Problem:
The customer asked how to connect related posts in the same form to add a new post.
Solution:
Guided that this will require the use of a generic field and the custom function attached to the 'cred_save_data' hook and shared the code example.
Solution:
The only way to allow users with a role lesser than Editor to add unfiltered HTML content to post fields is to elevate them to the roles of Editor or Administrator.
For administrators and editors, please note that the unfiltered HTML contents are enabled by default in Post and User Fields.