  A search for Higgs bosons that decay into a bottom quark-antiquark pair and
are accompanied by at least one additional bottom quark is performed with the
CMS detector. The data analyzed were recorded in proton-proton collisions at a
centre-of-mass energy of $\sqrt{s} =$ 13 TeV at the LHC, corresponding to an
integrated luminosity of 35.7 fb$^{-1}$. The final state considered in this
analysis is particularly sensitive to signatures of a Higgs sector beyond the
standard model, as predicted in the generic class of two Higgs doublet models
(2HDMs). No signal above the standard model background expectation is observed.
Stringent upper limits on the cross section times branching fraction are set
for Higgs bosons with masses up to 1300 GeV. The results are interpreted within
several MSSM and 2HDM scenarios.
