I am not aware of a way how you can filter the targets of a push notification by location and I doubt it is possible. Even if you find a way to do that, the task of gathering devices location seems pretty complicated to me. No idea occurs to me in this direction. Maybe you will need a server which will store device's latest location, but the way to achieve this goal is not known for me and it does not take a place in our support services scope.
I would recommend searching more in a public community forums like StackOverflow.
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