DocumenT Set/Flat set could be enhance to allow this concept of part item find in mid/high PDM/PLM systems

Below the concept demonstrate under SolidEfge/Sharepoint

https://youtu.be/y0uM8LchpfY?si=j-qjCZjL6vTWS6dJ&t=55

A similar concept exist under projectWise manage portfolio for rendition document (PDF).

Documet Set in the current state is more oriented into a manual operation, but could be integrate in a way, the Document Set will face the end user and as user add elements under this item, they will take the same doc number.