High-mass stars form at the junctions of dense fiber networks where large amounts of mass reservoir is present. In molecular clouds, these networks are often found to be responsible for mass accretion towards stellar nurseries. High resolution molecular line observations allow us to detangle narrow substructures and study the dynamics of molecular clouds. The hierarchical nature of molecular clouds show that the physical processes which govern the scales of star forming cores and the large scale molecular cloud are interconnected. Therefore, studies which aim to understand the dynamic mass accretion processes that lead to high-mass star formation require observations of a broad range of spatial scales.
Recently, using the NOEMA interferometer and the IRAM 30m telescope, we observed the Cygnus X star formation complex at 3.6 mm line and continuum emission within the framework of The Cygnus Allscale Survey of Chemistry and Dynamical Environments (CASCADE). In this work, we focus on the N2H+ observations of the DR21 filament. The high dynamic range of the CASCADE observations allow us to recover emission at spatial scales between ~15 pc and 0.02 pc. We present the identification of molecular cloud substructures, their physical and kinematic properties, and their dynamical connection to the large scale molecular cloud.