  In this paper, we introduce the class of bipartite peak-pit domains. This is
a class of Condorcet domains which include both the classical single-peaked and
single-dipped domains. Our class of domains can be used to model situations
where some alternatives are ranked based on a most preferred location on a
societal axis, and some are ranked based on a least preferred location. This
makes it possible to model situations where agents have different rationales
for their ranking depending on which of two subclasses of the alternatives one
is considering belong to. The class of bipartite peak-pit domains includes most
peak-pit domains for $n\leq 7$ alternatives, and the largest Condorcet domains
for each $n\leq 8$.
  In order to study the maximum possible size of a bipartite peak-pit domain we
introduce set-alternating schemes. This is a method for constructing
well-structured peak-pit domains which are copious and connected. We show that
domains based on these schemes always have size at least $2^{n-1}$ and some of
them have sizes larger than the domains of Fishburn's alternating scheme. We
show that the maximum domain size for sufficiently high $n$ exceeds $2.1973^n$.
This improves the previous lower bound for peak-pit domains $2.1890^n$ from
\cite{karpov2023constructing}, which was also the highest asymptotic lower
bound for the size of the largest Condorcet domains.
