Substitute for pumpkin pie filling
Puree of chayote with (nutmeg / clove / allspice / cinnamon / just sugar) (however you like it) works well. It's an Asian staple and available around the world in most Asian markets. It has no real detectable taste of its own, it just takes on the flavor of whatever you cook it with or put in it. 

If that's not available, you could sweeten a puree of butternut or regular squash and get the desired outcome.

With either method, be careful with your moisture content - you want it to be pretty much the same as pumpkin pie filling for the recipe you want to try.