We present the first direct search for exotic Higgs boson decays 𝐻→𝒜𝒜, 𝒜 →𝛾⁢𝛾 in events with two photonlike objects. The hypothetical particle 𝒜 is a low-mass spin-0 particle decaying promptly to a merged diphoton reconstructed as a single photonlike object. We analyze the data collected by the CMS experiment at √𝑠 =13  TeV corresponding to an integrated luminosity of 136  fb−1. No excess above the estimated background is found. We set upper limits on the branching fraction ℬ⁡(𝐻→𝒜⁢𝒜→4⁢𝛾) of (0.9–3.3)×10−3 at 95% confidence level for masses of 𝒜 in the range 0.1–1.2 GeV.