  Magnetic ordering of the first row transition metal intercalates of NbS$_2$
due to coupling between the conduction electrons and the intercalated ions has
been explained in terms of Fermi surface nesting. We use angle-resolved
photoelectron spectroscopy to investigate the Fermi surface topology and the
valence band structure of the quasi-two-dimensional layer compounds
Mn$_{1/3}$NbS$_2$ and Ni$_{1/3}$NbS$_2$. Charge transfer from the intercalant
species to the host layer leads to non-uniform, pocket selective doping of the
Fermi surface. The implication of our results on the nesting properties are
discussed.
