  Generic inhomogeneous steady states in an asymmetric exclusion process on a
ring with a pair of point bottlenecks are studied. We show that, due to an
underlying universal feature, measurements of coarse-grained steady-state
densities in this model resolve the bottleneck structures only partially.
Unexpectedly, it displays localization-delocalization transitions and
confinement of delocalized domain walls, controlled by the interplay between
particle number conservation and bottleneck competition for moderate particle
densities.
