  A search is presented for massive narrow resonances decaying either into two
Higgs bosons, or into a Higgs boson and a W or Z boson. The decay channels
considered are HH $\to \mathrm{b\overline{b}}\tau^{+}\tau^{-}$ and VH $\to
\mathrm{q\overline{q}}\tau^{+}\tau^{-}$, where H denotes the Higgs boson, and V
denotes the W or Z boson. This analysis is based on a data sample of
proton-proton collisions collected at a center-of-mass energy of 13 TeV by the
CMS Collaboration, corresponding to an integrated luminosity of 35.9 fb$^{-1}$.
For the TeV-scale mass resonances considered, substructure techniques provide
ways to differentiate among the hadronization products from vector boson decays
to quarks, Higgs boson decays to bottom quarks, and quark- or gluon-induced
jets. Reconstruction techniques are used that have been specifically optimized
to select events in which the tau lepton pair is highly boosted. The observed
data are consistent with standard model expectations and upper limits are set
at 95% confidence level on the product of cross section and branching fraction
for resonance masses between 0.9 and 4.0 TeV. Exclusion limits are set in the
context of bulk radion and graviton models: spin-0 radion resonances are
excluded below a mass of 2.7 TeV at 95% confidence level. In the spin-1 heavy
vector triplet framework, mass-degenerate W' and Z' resonances with dominant
couplings to the standard model gauge bosons are excluded below a mass of 2.8
TeV at 95% confidence level. There are the first limits for these decay
channels at $\sqrt{s} =$ 13 TeV.
