https://wccftech.com/how-to/sniper-elite-5-how-the-skill-tree-works-and-best-skills-to-unlock/

During your Sniper Elite 5 Campaign, you will earn XP points for completing objectives and killing enemies. When you reach enough XP, you will rank one level up and get a Skill Point. These can be spent on the Skills Menu and help you unlock new abilities, improve them and let you carry more items.

There are three Skill trees available in Sniper Elite 5, each one focused on a specific area: Combat, Equipment, and Body. Let’s see how they work and what are the best skills to unlock early in the game.