After spending an hour trying to figure out why the hierarchy setting on a self referencing relationship was greyed out I finally logged a ticket with Microsoft.

The ticket number is "2203150050002328 ". I was instructed by Microsoft that this setting is not available on all tables and it may be best to raise an idea.

So, it would be great if Microsoft allowed us to customise OOB / Custom tables to allow the use of hierarchy settings as the visual is useful in more areas than just Accounts (Parent>Child).

In this scenario, a client has multiple subscription lists (marketing list) in D365 CRM. However if a customer opts in to Energy they're asked to specify their additional areas of interest in energy (child subscription lists). The marketing team markets to contacts based on these subscriptions.

It would be useful for Marketing to know if a subscription list is a parent and be able to see the number of members on each child subscription list at a click of a button.