Exactly. From a TS cert standpoint, the sister facility in Europe may be your customer.
Does the US facility direct the design group and and tell them what and how to design?
To approach the TS certification structure by fracturing the organization into multiple, separate cert scopes but then treat all locations as one organization since that what it is outside of the TS certification world, is confusing, ineffective and inefficient. Definition of inputs, outputs, outsourcing, remote supporting sites, customers, suppliers, design responsibility, general responsibility and authority, all get muddied and confusing when an organization has multiple TS certs within the overall organization especially with a design group that is included in multiple certs.