Split the move to location in two parts, first find a location where the turning is supposed to happen, then move from there to the final location.
If this is supposed to be some turn-based implementation for a game, I advice against using the built-in navmesh tools and building your own (look into Dijkstra) or getting a marketplace asset that does it for you.
The tools provided by Unreal are made with games such as UT in mind.