The increasing demand for data traffic can be met by effective utilization of spectrum through flexible duplexing in heterogeneous networks (HetNets). By effectively switching the transmission modes between full duplex (FD) and half duplex (HD), an elevated system performance can be achieved as HD mode provides better results in regions where self interference for FD is much higher than the desired power. We, in this paper, investigate a distance-based duplexing scheme in a two-tier HetNet that exploits dual slope path loss model in both tiers. In our proposed scheme, a user connects to a base station (BS) based on maximum received power after which it decides to operate in either FD or HD depending upon a thresholding distance. Simulation results show that the performance of the system depends upon the thresholding distance for flexible duplexing mode and the path loss exponents of dual slope model. Results for sum rate and outage probabilities are provided for both uplink and downlink transmissions.