  Linking structure is a new concept characterizing topological semimetals,
which indicates the interweaving of gap-closing nodes at the Fermi energy
($E_F$) with other nodes below $E_F$. As the number of linked nodes can be
changed only via pair-creation or pair-annihilation, a linked node is more
stable and robust than ordinary nodes without linking. Here we propose a new
type of a linked nodal structure between a nodal line (nodal surface) at $E_F$
with another nodal line (nodal surface) below $E_F$ in two-dimensional
(three-dimensional) spinless fermion systems with $\mathcal{IT}$ symmetry where
$\mathcal{I}$ and $\mathcal{T}$ indicate inversion and time-reversal
symmetries, respectively. Because of additional chiral and rotational
symmetries, in our system, a double band inversion creates a pair of linked
nodes carrying the same topological charges, thus the pair are unremovable via
a Lifshiftz transition, which is clearly distinct from the cases of the linked
nodes reported previously. A realistic tight binding model and effective theory
are developed for such a linking structure. Also, using density functional
theory calculations, we propose a class of materials, composed of stacked
bilayer graphene with Kekul\'{e} texture, as a candidate system hosting the new
type of the linked nodal structure.
