If you ever need to know which payout a payment was included in, you can:
First, head to the billing tab
Next, click to open the details of that payment by clicking the '+' symbol
Then, look for the payout ID
Finally, at the bottom of the Billing Tab you'll see 'Related Payouts' this will have all the details of the payout that was transferred to your bank that included this payment. Note: Payouts include multiple payments and refunds that are rolled together over a two day period.