  Star-forming molecular clouds are characterised by the ubiquity of
intertwined filaments. The filaments have been observed in both high- and
low-mass star-forming regions, and are thought to split into collections of
sonic fibres. The locations where filaments converge are termed hubs, and these
are associated with the young stellar clusters. However, the observations of
filamentary structures within hubs at distances require a high angular
resolution that limits the number of such studies conducted so far. The
integral shaped filament of the Orion A molecular cloud is noted for harbouring
several hubs within which no filamentary structures have been observed so far.
The goal of our study is to investigate the nature of the filamentary
structures within one of these hubs, which is the chemically rich hub OMC-2 FIR
4, and to analyse their emission with high density and shock tracers. We
observed the OMC-2 FIR 4 proto-cluster using Band 6 of the ALMA in Cycle 4 with
an angular resolution of ~0.26"(100 au). We analysed the spatial distribution
of dust, the shock tracer SiO, and dense gas tracers (i.e., CH$_{3}$OH, CS, and
H$^{13}$CN). We also studied gas kinematics using SiO and CH3OH maps. Our
observations for the first time reveal interwoven filamentary structures within
OMC-2 FIR 4 that are probed by several tracers. Each filamentary structure is
characterised by a distinct velocity as seen from the emission peak of
CH$_{3}$OH lines. They also show transonic and supersonic motions. SiO is
associated with filaments and also with multiple bow-shock features. In
addition, for the first time, we reveal a highly collimated SiO jet
(~1$^{\circ}$) with a projected length of ~5200 au from the embedded protostar
VLA15. Our study shows that multi-scale observations of these regions are
crucial for understanding the accretion processes and flow of material that
shapes star formation.
