Beyond Fifth Generation (B5G) network aims to provide a very high data rate with minimum latency to an ultra-dense user environment. To achieve this demand, the possible approaches are network-centric and device-centric approach. In a network-centric approach, a new frequency band is introduced, and the existing network infrastructure is modified. The device-centric approach does not require any modification in the existing network infrastructure, and the demand of B5G network is achieved through optimum resource allocation methodology. Device-to-Device (D2D) is an effective device-centric approach that supports the B5G network. In this paper, we propose a dynamic sectorization technique in which eNodeB (eNB) varies the number of sectors dynamically in the network and allocates the Resource Block (RB) to D2D users. Sectoring improves Signal-to-Interference-Noise-Ratio (SINR) and network performance. We derive an expression for the probability of successful transmission and threshold to make a decision on the number of sectors based on available RBs and D2D users in the network. Further, dynamic sectoring helps eNB to perform parallel processing for reducing the denial of the request. Simulation results validate the probability of successful transmission of D2D pairs with available RBs and the effectiveness of parallel processing to reduce the denial of request with improved SINR. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.