  Quantum steering is commonly shared among multiple observers by utilizing
unsharp measurements. However, their usage is limited to local measurements and
is not suitable for nonlocal-measurement-based cases. Here, we present a novel
approach in this study, suggesting a highly efficient technique to construct
optimal nonlocal measurements by utilizing quantum ellipsoids to share quantum
steering. This technique is suitable for any bipartite state and offers
benefits even in scenarios with a high number of measurement settings. Using
the Greenberger-Horne-Zeilinger state as an illustration, we show that
employing unsharp nonlocal product measurements can activate the phenomenon of
steering sharing in contrast to using local measurements. Moreover, our
findings demonstrate that nonlocal measurements with unequal strength possess a
greater activation capability compared to those with equal strength. Our
activation method differs from previous ones as it eliminates the need to copy
the shared states or diminish other quantum correlations, thus making it
convenient for practical experimentation and conservation of resources.
