Measurements of branching fractions of $ {D}^{0}\to {K}^{-}3{\pi }^{+}2{\pi }^{-}$, $ {D}^{0}\to {K}^{-}2{\pi }^{+}{\pi }^{-}2{\pi }^{0}$, and $ {D}^{+}\to {K}^{-}3{\pi }^{+}{\pi }^{-}{\pi }^{0}$

Utilizing $ 7.9\text{}\text{}{\mathrm{fb}}^{-1}$ of $ {e}^{+}{e}^{-}$ collision data taken with the BESIII detector at the center-of-mass energy of 3.773 GeV, we report the measurements of absolute branching fractions of the hadronic decays $ {D}^{0}\to {K}^{-}3{\pi }^{+}2{\pi }^{-}$, $ {D}^{0}\to {K}^{-}2{\pi }^{+}{\pi }^{-}2{\pi }^{0}$ and $ {D}^{+}\to {K}^{-}3{\pi }^{+}{\pi }^{-}{\pi }^{0}$. The $ {D}^{0}\to {K}^{-}3{\pi }^{+}2{\pi }^{-}$ decay is measured with improved precision, while the latter two decays are observed with statistical significance higher than $ 5\sigma $ for the first time. The absolute branching fractions of these decays are determined to be $ \mathcal{B}({D}^{0}\to {K}^{-}3{\pi }^{+}2{\pi }^{-})=(1.35\pm 0.23\pm 0.08)\times {10}^{-4}$, $ \mathcal{B}({D}^{0}\to {K}^{-}2{\pi }^{+}{\pi }^{-}2{\pi }^{0})=(19.0\pm 1.1\pm 1.5)\times {10}^{-4}$, and $ \mathcal{B}({D}^{+}\to {K}^{-}3{\pi }^{+}{\pi }^{-}{\pi }^{0})=(6.57\pm 0.69\pm 0.33)\times {10}^{-4}$, where the first uncertainties are statistical and the second systematic.