Measurements of the branching fractions of ${\eta }_c\to K^{+}{K}^{-}{\pi }^0$, $K_S^0{K}^{\pm }{\pi }^{\mp }$,$2({\pi }^{+}{\pi }^{-}{\pi }^0)$, and $p\bar{p}$

Using data samples collected with the BESIII detector at center-of-mass energies $\sqrt{s}=4.23,4.26,4.36,$ and $4.42$~\rm{GeV}, we measure the branching fractions of ${\eta }_c\to K^{+}{K}^{-}{\pi }^0$, $K_S^0{K}^{\pm }{\pi }^{\mp }$, $2({\pi }^{+}{\pi }^{-}{\pi }^0)$, and $p\bar{p}$, via the process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{h}_c$, $h_c\to \gamma {\eta }_c$. The corresponding results are $(1.15\pm 0.12\pm 0.10)\mathrm{\%}$, $(2.60\pm 0.21\pm 0.20)\mathrm{\%}$, $(15.2\pm 1.8\pm 1.7)\mathrm{\%}$, and $(0.120\pm 0.026\pm 0.015)\mathrm{\%}$, respectively. Here the first uncertainties are statistical, and the second ones systematic. Additionally, the charged track multiplicity of ${\eta }_c$ decays is measured for the first time.