Have a look at this:
https://www.youtube.com/watch?v=hZ6bHlF5VK0
It is from 2017 but it gives you an idea of how the archive application can be designed (I have no connection with Finit). I have spoken to a number of experienced OS consultants about this and a common design is this 'no hierarchy' dimension. A client was talking about doing it but then decided not to so I haven't any experience myself. What I haven't worked out is how you write reports/cube views bringing the archived data into the current OS application.
