Hi, there are different options, some of which are:
(1) retrieve the historical data from your regional ERPs and load the data on the "new" level also for historical data (difficult for statutory consolidation, more feasible for management reporting in my view)
(2) create a HISTORY cube structure (basically a duplication of your mentioned cubes) where you assign only your "Consolidated Corp" chart of accounts to all cubes so that also Region 1 and Region 2 use this account hierarchy on an input level. And then in your reports you pull the information from your Actual HISTORY cube e.g. up until 2023 and from 2024 onwards you pull the data from your new Actual scenario that has this extended granularity. You could also set up a UD8 reporting member for this if needed.
(3) create dummy input accounts for parent level input in the regional structures for historical data only (I would personally try not to do this as I prefer a new clean chart of accounts preferably without such members used for history only)
You could also do e.g. (1) and (2) where you create this cube structure for your historical statutory consolidation which has been audited and load more granular historical data into the non-historical cubes for management reporting purposes.
