Dear Vincent,
The change of valuation currency for a valuation area will cause inconsistencies of the data, therefore it is not recommended. In Treasury Management we do not know a group currency, you may consider to create a new valuation area, and set the valuation currency = group currency (USD here).
Please note that you can have a Valuation Area currency different from Company Code currency but postings to FI will only be possible:
- in case a special ledger (SL) is used and
- the valuation currency corresponds to the second or third local currency of the company code (like group currency)
You can check the help of the mentioned customizing and note 1557972 for more information about this possibility.
Best regards,
Jasmine