The percentage that we show as potential return is the annual interest rate that is charged on a decreasing balance loan.
For example if you lend a Borrower €10,000 at a 10.30% interest rate over 36 months, the monthly repayments to you will be €324.08.
So you will get back €11,666.96 in total (i.e. a return of €1,666.96, or 16.7% of the loaned amount). Dividing that 16.7% by three years gets to 5.7%, but that 5.7% is not the available rate of return, because it's not compounded.
In order to achieve an annual rate of return of 10.3%, you'd simply reinvest the monthly repayments from this loan into other loans to receive the benefits of compound interest.