Hi @atrevido
I’m afraid I don’t quite understand your question. Could you please explain it to me in more details?
If you want to update the custom field value for all of the posts in a category, I think you need to loop trough the posts and then use the update_field() function to update it. This page should give you more idea about it: https://www.advancedcustomfields.com/resources/update_field/.
Thanks 🙂
