  We discuss low-temperature multipole states of Nd-based filled skutterudites
by analyzing a multiorbital Anderson model with the use of a numerical
renormalization group method. In order to determine the multipole state, we
take a procedure to maximize the multipole susceptibility matrix. Then, it is
found that the dominant multipole state is characterized by the mixture of 4u
magnetic and 5u octupole moments. The secondary state is specified by 2u
octupole. When we further take into account the coupling between $f$ electrons
in degenerate $\Gamma_{67}^{-}$ ($e_{\rm u}$) orbitals and dynamical
Jahn-Teller phonons with $E_{\rm g}$ symmetry, quadrupole fluctuations become
significant at low temperatures in the mixed multipole state with 4u magnetic
and 5u octupole moments. Finally, we briefly discuss possible relevance of the
present results to actual Nd-based filled skutterudite compounds.
