Recent advancements in flexible pavement structures involve incorporating geocomposites (GCs) within the granular layers. These GC integration in the granular layers of the pavement sections primarily aim to improve hydraulic performance, with a secondary advantage of enhanced structural integrity. The effectiveness of GCs is attributed to their increased drainage capabilities and is influenced by factors like placement depth, in-plane flow capacity, rib pattern and spacing, and filter opening size. This study investigates the impact of GC embedment location within the granular subbase layer (GSB) on the hydraulic performance of the pavement system. Large-scale permeameter tests are conducted to systematically evaluate the effect of varying GC embedment depths (at H/4, H/2, 3H/4, and H from the top of the subbase) on key hydraulic parameters, i.e., in-plane drainage efficiency. The results reveal that embedding the GC at the mid-section (or at greater embedment locations) of the GSB layer has led to significantly higher in-plane permeability than other configurations. This highlights the crucial role of precise GC positioning for optimizing drainage efficiency within the GSB. By demonstrating the advantages of GC placement through experimentation, this research offers valuable insights to guide the design and implementation of GSB systems.