This is a setup for a skill tree for a game about Greek mythology, which I created using Figma.
There are three different categories of skills: movement, attack and personality. Each category has a corresponding pillar with three skill slots.
At each level, the player gets three skill points. Within a level, the player can pick up to one skill per category, each costing one point. Points can be stacked on a single skill to increase its power, but this uses multiple slots in that pillar, limiting variety within that category. Skills chosen in previous levels cannot be selected again.
At the fourth level, the player transforms into a character based on their chosen skills (in this prototype: centaur).
Click the buttons in the image on the left or at this link to traverse through the prototype. It contains only contains one possible path; click anywhere within the prototype window to see which element is clickable (it will light up).