HANA SQL Logic or Calculation view Model level Approach for time dependent role mapping

Question

I have a Time dependent Master data table – DRNUMBER Recently with new CLASS – ‘1TC’, ECC folks introduced Role information. Earlier with CLASS - ‘1JL’ role information will not be available. CLASS - 1JL is somewhat detail level and CLASS - 1TC is aggregated level if same role is performed with continued dates.

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Expected output should look like below. How to achieve this in HANA - SQL and if Calculation view Model level is possible how it is…..

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