The solution to this problem is a family of techniques called “order independent transparency”, which are generally too expensive to use in games. Shadows of Mordor and Tomb Raider use OIT techniques for the main character’s hair, and apparently Grid 2 uses it for roadside vegetation; other than those specific cases, I’m not aware of any modern engines with robust OIT support.
Unless some kind of OIT solution is added by Nvidia for their hairworks branch (which I think might be on hold right now?), there won’t be a solution for this in UE4’s foreseeable future.
What you might consider instead is changing your design so that it can’t overlap itself, changing your materials to not use transparency, or using a transparency blending mode where the artifacts will be invisible, such as additive blending. You could also try using the dithered temporal transparency material function with a masked material, but in my experience it gives unconvincing results.