You have 8,000 BSW staked in the holder and your referral link has a profit-sharing option of 50%. Your invited friend made a swap on Biswap for 10,000 USDT. Given this data, we can conclude that a trading fee of 10 USDT was paid. As a result, your referral reward is 0.9 USDT (10 USDT x 18% x 50%). If an exchange rate is 1 BSW = 1 USDT, you will receive 0.9 BSW on your referral balance.