This is quite easy to do... You don't have to actually manage to complete the survival to get this achievement.
There are two filters to create - a basic and an advanced. You only have to create the basic filter for this (and only need the basic to enter the dark zone. The advanced filter just lets you get to underground parts etc in the DZ). To create the basic filter, you need 2xBlue Fabric and 2xBlue Tools!
You cannot craft the Flare Gun until you get to the Dark Zone. Once there, you need 2xYellow Weapon Parts and 1xYellow Division Tech. There are a number of places you can pick up division tech in the DZ, but you will get a piece when you pick up your anti-virals. If you have division tech, you don't need to have retrieved your anti-virals to craft the Flare Gun.
NOTE: If you come across a downed player in the DZ that has crafted the flare gun, picking this up still counts as if you have crafted it!