  We derive a set of constraints, which we will call hierarchy constraints
(HCs), on scattering amplitudes of an arbitrary multistate Landau-Zener model
(MLZM). The presence of additional symmetries can transform such constraints
into nontrivial relations between elements of the transition probability
matrix. This observation can be used to derive complete solutions of some MLZMs
or, for models that cannot be solved completely, to reduce the number of
independent elements of the transition probability matrix.
