  Strong correlations lead to emergent excitations at low energies. When
combined with symmetry constraints, they may produce topological electronic
states near the Fermi energy. Within this general framework, here we address
the topological features in iron-based superconductors. We examine the effects
of orbital-selective correlations on the band inversion in the iron
chalcogenide FeSe$_{x}$Te$_{1-x}$ near its doping of optimal superconductivity,
within a multiorbital model and using a $U(1)$ slave spin theory. The orbital
selectivity of the quasiparticle spectral weight, along with its counterpart of
the energy level renormalization, leads to a band inversion and Dirac node
formation pinned to the immediate vicinity of the Fermi energy. Our work
demonstrates both the naturalness and robustness of the topological properties
in FeSe$_{x}$Te$_{1-x}$, and uncovers a new setting in which strong
correlations and space-group symmetry cooperate in generating strongly
correlated electronic topology.
