You mention the BosdynNavigateToAnchor Node-action in the Doku (https://dev.bostondynamics.com/docs/concepts/autonomy/missions_service) and it exists in nodes.proto but was forgotten (i suppose) to be added to the Node.type options. Therefore SDK Users cant use this feature in a behaviour tree:
nodes_pb2.Node().bosdyn_navigate_to_anchor // AttributeError