Try:
#pragma link C++ nestedclass;
#pragma link C++ nestedtypedef;
#pragma link C++ namespace dd4hep;
#pragma link C++ defined_in namespace dd4hep;
#pragma link C++ namespace dd4hep::rec;
#pragma link C++ defined_in namespace dd4hep::rec;
#pragma link C++ class dd4hep::rec::Vector3D+;
#pragma link C++ class std::vector<dd4hep::rec::Vector3D>+;