  Symmetry-resolved entanglement is a useful tool for characterizing
symmetry-protected topological states. In two dimensions, their entanglement
spectra are described by conformal field theories but the symmetry resolution
is largely unexplored. However, addressing this problem numerically requires
system sizes beyond the reach of exact diagonalization. Here, we develop tensor
network methods that can access much larger systems and determine universal and
nonuniversal features in their entanglement. Specifically, we construct
one-dimensional matrix product operators that encapsulate all the entanglement
data of two-dimensional symmetry-protected topological states. We first
demonstrate our approach for the Levin-Gu model. Next, we use the cohomology
formalism to deform the phase away from the fine-tuned point and track the
evolution of its entanglement features and their symmetry resolution. The
entanglement spectra are always described by the same conformal field theory.
However, the levels undergo a spectral flow in accordance with an insertion of
a many-body Aharonov-Bohm flux.
