  Parity-time ($\mathcal{PT}$) symmetry is a cornerstone of non-Hermitian
physics as it ensures real energies for stable experimental realization of
non-Hermitian phenomena. In this work, we propose $\mathcal{PT}$ symmetry as a
paradigm for designing rich families of higher-dimensional non-Hermitian states
with unique bulk, surface, hinge or corner dynamics. Through systematically
breaking or restoring $\mathcal{PT}$ symmetry in different sectors of a system,
we can selectively activate or manipulate the non-Hermitian skin effect (NHSE)
in both the bulk and topological boundary states. Some fascinating phenomena
include the directional toggling of the NHSE, and the flow of boundary states
without chiral or dynamical pumping, developed from selective boundary NHSE.
Our results extend richly into 3D or higher, with more sophisticated interplay
with selective bulk and boundary NHSE and charge-parity ($\mathcal{CP}$)
symmetry. Based on non-interacting lattices, $\mathcal{PT}$-activated NHSEs can
be observed in various optical, photonic, electric and quantum platforms that
admit gain/loss and non-reciprocity.
