  Thin NbSe$_2$ retains superconductivity at high in-plane magnetic field up to
30 T. In this work we construct an atomically thin, all van der Waals SQUID, in
which current flows between NbSe$_2$ contacts through two parallel graphene
weak links. This fully planar device remains uniquely stable at high in-plane
field. This enables tracing the evolution of the critical current interference
patterns as a function of the field up to 4.5 T, allowing nm-scale sensitivity
to deviations from a perfect atomic plane. We present numerical methods to
retrieve asymmetric current distributions J$_0$ from measured interference
maps, and suggest a new application of the dual junction geometry to probe the
current density in the absence of phase information. The interference maps
exhibit a striking field-driven transition, indicating a redistribution of
supercurrents to narrow channels. Our results suggest the existence of a
preferred conductance channel with an exceptional stability to in-plane
magnetic field.
