I introduced How to link the due date of a specific task or subtask into a custom field of a portfolio before. It was very complicated.
Thanks to a new automation functionality, finally we can do it by a simple automation (rule)!
Please try the following.
① Select a project
②-1 Choose the action [Change custom field to…] and click a portfolio
②-2 Choose the custom field which you made as a date type in a portfolio
②-3 select Due date for [select a date]
The custom field in a portfolio would change when the due date of a specific task if you set up the above.




