  We present a new, multi-dimensional implementation of the Advanced Spectral
Leakage (ASL) scheme with the purpose of modelling neutrino-matter interactions
in neutron star mergers. A major challenge is the neutrino absorption in the
semi-transparent regime, which is responsible for driving winds from the merger
remnant. The composition of such winds is crucial in the understanding of the
electromagnetic emission in the recently observed macronova following GW170817.
Compared to the original version, we introduce an optical-depth-dependent flux
factor to model the average angle of neutrino propagation, and a modulation
that accounts for flux anisotropies in non-spherical geometries. We scrutinise
our approach by first comparing the new scheme against the original one for a
spherically symmetric core-collapse supernova snapshot, both in 1D and in 3D,
and additionally against a two-moment (M1) scheme as implemented in 1D into the
code GR1D. The luminosities and mean energies agree to a few percents in most
tests. Finally, for the case of a binary merger remnant snapshot we compare the
new ASL scheme with the M1 scheme that is implemented in the Eulerian adaptive
mesh refinement code FLASH. We find that the neutrino absorption distribution
in the semi-transparent regime is overall well reproduced. Both approaches
agree to within $\lesssim 15\%$ for the average energies and to better than
$\sim 35 \%$ in the total luminosities.
