Thank you for asking this question on the Microsoft Q&A Platform.
I understand that you require to synchronize your AD DS to more than one Azure AD Tenant.
That requirement is supported
Please read all the use cases and considerations from the following link https://learn.microsoft.com/en-us/azure/active-directory/hybrid/connect/plan-connect-topologies#sync-ad-objects-to-multiple-azure-ad-tenants
Hope this helps!
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