  We present an analysis of the dense gas structures in the immediate
surroundings of the massive young stellar object (MYSO) W42-MME, using the
high-resolution (0$''$.31$\times$0$''$.25) ALMA dust continuum and molecular
line data. We performed a dendrogram analysis of H$^{13}$CO$^{+}$ (4-3) line
data to study multi-scale structures and their spatio-kinematic properties, and
analyzed the fragmentation and dynamics of dense structures down to $\sim$2000
AU scale. Our results reveal 19 dense gas structures, out of which 12 are
leaves and 7 are branches in dendrogram terminology. These structures exhibit
transonic-supersonic gas motions (1$<\mathcal{M}<5$) with overvirial states
($\alpha_{\rm vir}\geq2$). The non-thermal velocity dispersion-size relation
($\sigma_{\rm nt}-L$) of dendrogram structures shows a weak negative
correlation, while the velocity dispersion across the sky
($\delta\mathit{V_{\rm lsr}}$) correlates positively with structure size ($L$).
Velocity structure function ($S_{2}(l)^{1/2}$) analysis of H$^{13}$CO$^{+}$
data reveals strong power-law dependencies with lag ($l$) up to a scale length
of $\lesssim$ 6000 AU. The mass-size ($M-R$) relation of dendrogram structures
shows a positive correlation with power-law index of 1.73$\pm$0.23, and the
leaf L17 hosting W42-MME meets the mass-size conditions for massive star
formation. Blue asymmetry is observed in the H$^{12}$CO$^{+}$ (4-3) line
profiles of most of the leaves, indicating infall. Overall, our results
observationally support the hierarchical and chaotic collapse scenario in the
proximity of the MYSO W42-MME.
