  The CMS phase II track trigger may allow for a displaced dimuon vertex
trigger with qualitatively lower $p_T$ thresholds than existing dimuon
triggers. With this technique, we show that the CMS reach for exotic $B$-meson
decays involving a displaced dimuon resonance, such as a light, Higgs-mixed
scalar, can be competitive with that of LHCb and Belle II.
