  Resonant soft x-ray Bragg diffraction at the Dy M$_{4,5}$ edges has been used
to study Dy multipoles in the combined magnetic and orbitally ordered phase of
DyB$_2$C$_2$. The analysis incorporates both the intra-atomic magnetic and
quadrupolar interactions between the 3d core and 4f valence shells.
Additionally, we introduce to the formalism the interference of magnetic and
nonmagnetic oscillators. This allows a determination of the higher order
multipole moments of rank 1 (dipole) to 6 (hexacontatetrapole). The strength of
the Dy 4f multipole moments have been estimated at being between 7 and 78 % of
the quadrupolar moment.
