Hi jlmccormack,
Unfortunately, if you want to display the notes of the child record in the parent record, there is currently no OOTB way. We can only create the same notes with the child records for the parent record to achieve this requirement.
We will use power automate to create notes.
Whenever a note is created, flow is automatically run, the condition is that the record related to this note has a parent record, then create the same note for this parent record.
In this way, the same note as the child record will appear in the parent record.
Please let me know if you accept this solution, and if so, I will provide you with screenshots of specific steps.
