  Recently discovered heavy fermion CeRh$_{2}$As$_{2}$ compound crystallizes in
the nonsymmorphic $P4/nmm$ symmetry, which enables the occurrence of
topological protection. Experimental results show that this material exhibits
unusual behavior, which is manifested by the appearance of two superconducting
phases. In this work, we uncover and discuss a role of Rh$_{2}$As$_{2}$ layers
and their impact on the electronic and dynamical properties of the system. The
location of Ce atoms between two non-equivalent layers allows for the
realization of hidden orbital order. We point out that the electronic band
structure around the Fermi level is associated mostly with Ce $4f$ and Rh $4d$
orbitals and suggest the occurrence of the Lifshitz transition induced by the
external magnetic field. We discuss also the role played by the $f$--$d$
orbital hybridization in the electronic band structure.
