Hi Suzy,
ACF support team here.
Thank you for reaching out! You’re actually just one small step away from getting those parent/child relationships working perfectly.
In WordPress, toggling the “Hierarchical” setting to true allows the post type to support parent/child relationships in the database, but it does not automatically add the UI dropdown to the block editor. To make the “Parent” selector appear on your post editing screen, you also need to explicitly tell WordPress to load that specific interface box. You can do this by navigating to your post type in ACF, scrolling down to the “Advanced Configuration” section, clicking the “Supports” tab, and checking the box for “Page Attributes”.
Once you save those changes, you should see the Page Attributes meta box (containing the Parent dropdown) appear right in your post editor! If you try this and it still isn’t showing up, please feel free to create a support ticket with us so we can dig a little deeper into your specific setup.
Best regards,
Patroba
Thank you so much Patroba! That was precisely the step I was missing. I appreciate the quick response.