  The polymorph of ${\rm 8-Pmmn}$ borophene is an anisotropic Dirac material
with tilted Dirac cones at two valleys. The tilting of the Dirac cones at two
valleys are in opposite direction, which manifests itself via valley dependent
Landau levels in presence of an in-plane electric field (Hall field). The
sensitivity of the Landau levels on valley index causes valley polarized
magnetotransport properties in presence of a Hall field, which is in contrast
to the monolayer graphene with isotropic non-tilted Dirac cones. The
longitudinal conductivity and Hall conductivity are evaluated by using linear
response theory in low temperature regime. An analytical approximate form of
longitudinal conductivity is also obtained to reveal how the tilting of the
Dirac cones affects the frequency of longitudinal conductivity oscillation
(Shubnikov-de Hass oscillation). On the other hand, Hall conductivity exhibits
graphene-like plateau excepts the appearance of valley dependent steps which is
purely attributed to the Hall field induced lifting valley degeneracy in Landau
levels. Another noticeable point is that if the real magnetic field is replaced
by the strain induced pseudo magnetic field then the electric field looses its
ability to cause valley polarized transport.
