The emergence, amplification, and manipulation of chiroptical activity in self-assembled nanostructures, including circularly polarized absorbance and luminescence (CPL), remain considerable challenges. Here, we report the high-throughput synthesis of nanostructures with finely tailored chiroptical activities. Two fully π-conjugated benzimidazoles formed H-bonded complexes with natural hydroxyl acids (tartaric acid and mandelic acid), which self-assembled into diversified macroscopically chiral nanostructures. Synergistic coassembly allows for the emergence of Cotton effects and CPL with high dissymmetry -factors ( up to 8 × 10, up to 3 × 10). The tartaric acid coassembled system exhibits enantiomer-independent left-handed CPL, which transforms into a cooperative ternary coassembly appended with enantiomer-resolved CPL with extended emission wavelength upon selective transition metal ion chelation. This H-boned coassembly system provides a vast number of chiral nanostructures with flexibly tuned Cotton effects and CPL, which also behaves as a selective chiroptical sensor to metal ions.