A group of Nazi solider’s try to cut off Russian forces by taking a shortcut through an abandoned mine, but something begins to hunt them through the dark tunnels.

What’s the inciting incident? It should be when the first person turns up dead in the mine. It’s the event that kick starts the story and the story is about them being hunted.

Does the thing that hunts them relate in any way to them being Nazis? The fact that they’re Nazis needs to be relevant. Why Nazis? Why this time period?

You need a single protagonist ideally. The leader of this group.

You’re also making Nazis the heroes of this story… is that your intention? You have to make the audience empathise with a group of Nazis and want them to survive. That could prove difficult although there are films have Germans in WWII as the protagonists – Das Boot springs to mind. Downfall is another although I’m not sure the audience is ever rooting for Hitler…

If the protagonist is actually the person/thing that is hunting them through the mine, the logline needs to be written from their perspective.

(You don’t need an apostrophe on soldiers btw).