  We propose and experimentally realize a class of quasi-one-dimensional
topological lattices whose unit cells are constructed by coupled multiple
identical resonators, with uniform hopping and inversion symmetry. In the
presence of path-induced effective zero hopping within the unit cells, the
systems are characterized by complete multimerization with degenerate $-1$
energy edge states for open boundary condition. Su-Schrieffer-Heeger subspaces
with fully dimerized limits corresponding to pairs of nontrivial flat bands are
derived from the Hilbert spaces. In particular, topological bound states in the
continuum (BICs) are inherently present in even multimer chains, manifested by
embedding the topological bound states into a continuous band assured by
bulk-boundary correspondence. Moreover, we experimentally demonstrate the
degenerate topological edge states and topological BICs in inductor-capacitor
circuits.
