  Soft X-ray resonant scattering (XRS) has been used to observe directly, for
the first time, the ordering of localized electronic states on both the Mn and
Tb sites in multiferroic TbMnO$_3$. Large resonant enhancement of the X-ray
scattering cross-section were observed when the incident photon energy was
tuned to either the Mn $L$ or Tb $M$ edges which provide information on the Mn
3d and Tb $4f$ electronic states, respectively. The temperature dependence of
the XRS signal establishes, in a model independent way, that in the
high-temperature phase (28 K $\leq$ T $\leq$ 42 K) the Mn 3d sublattices
displays long-range order. The Tb $4f$ sublattices are found to order only on
entering the combined ferroelectric/magnetic state below 28 K. Our results are
discussed with respect to recent hard XRS experiments (sensitive to spatially
extended orbitals) and neutron scattering.
