As a leader, for every person directly under you (Level 1), you get a 10% bonus. So if you invest $100, each Level 1 member earns you $10. If you have 2 members in Level 1, you'll earn $20, and so on.
When your Level 1 member has people under them in Level 2, you also get a 5% indirect bonus. With an investment of $100, each Level 2 member earns you $5. Based on the figure above, when there are a total of 6 people in Level 2, you'll earn an additional $30.