Filamentary structures are ubiquitously seen in the interstellar medium. The concentrated molecular mass in the filaments allows fragmentation to occur in a shorter timescale than the timescale of the global collapse. Such hierarchical fragmentation may further assist the dissipation of excessive angular momentum. It is crucial to resolve the morphology and the internal velocity structures of the molecular filaments observationally. We perform 0farcs5-2farcs5 angular resolution interferometric observations toward the nearly face-on OB cluster-forming region G33.92 0.11. Observations of various spectral lines, as well as the millimeter dust continuum emission, consistently trace several ~1 pc scale, clumpy molecular arms. Some of the molecular arms geometrically merge to an inner 3.0 2.8- 1.4 × 103 M &sun;, 0.6 pc scale central molecular clump, and may directly channel the molecular gas to the warm (~50 K) molecular gas immediately surrounding the centrally embedded OB stars. The NH3 spectra suggest a medium turbulence line width of FWHM spectra suggest a medium turbulence line width of FWHM -1 in the central molecular clump, implying a gsim10 times larger molecular mass than the virial mass. Feedbacks from shocks and the centrally embedded
