P(VDF-TrFE)/TiO2/PDMS-based hybrid nanogenerators with excellent piezoelectric performance are of particular interest for the development of sensors, wearable devices, and low-cost biomechanical energy harvesters. In this work, hybrid nanogenerator (HNG) is designed to enhance the energy output by integrating piezoelectric and triboelectric effects. P(VDF-TrFE)/TiO2 nanocomposites are synthesized using electrospinning to design hybrid nanogenerator for energy harvesting from a manual activity. The hybrid nanogenerator device generated 5.36 µA current across 10 MΩ resistor and 52 V electric voltage. An analysis of the effect of varying TiO2 on hybrid nanogenerators is reported here for the first time. The best material for biomechanical energy harvesting applications is selected using a multi-criteria decision-making (MCDM) based material selection and optimization technique TODIM, along with a sensitivity study. SA-4 type nanocomposite is the most suitable material as per the TODIM approach. This nanogenerator shows better performance than most nanogenerators designed with complex and sophisticated approaches.