  Measurements of the production of muons from heavy-flavour hadron decays in
Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = $5.02$ and $2.76$ TeV using the
ALICE detector at the LHC are reported. The nuclear modification factor $R_{\rm
AA}$ at $\sqrt{s_{\rm NN}}$ = 5.02 TeV is measured at forward rapidity ($2.5 <
y <4$) as a function of transverse momentum $p_{\rm T}$ in central,
semi-central, and peripheral collisions over a wide $p_{\rm T}$ interval, $3 <
p_{\rm T} < 20$ GeV/$c$, in which muons from beauty-hadron decays are expected
to take over from charm as the dominant source at high $p_{\rm T}$ ($p_{\rm T}
> 7$ GeV/$c$). The $R_{\rm AA}$ shows an increase of the suppression of the
yields of muons from heavy-flavour hadron decays with increasing centrality. A
suppression by a factor of about three is observed in the $10\%$ most central
collisions. The $R_{\rm AA}$ at $\sqrt{s_{\rm NN}}$ = 5.02 is similar to that
at 2.76 TeV. The precise $R_{\rm AA}$ measurements have the potential to
distinguish between model predictions implementing different mechanisms of
parton energy loss in the high-density medium formed in heavy-ion collisions.
They place important constraints for the understanding of the heavy-quark
interaction with the hot and dense QCD medium.
