View the order in Tables app
Tap Leave Table next to Guest 2, who is leaving
Tap Pay for Items
Tap Pay to confirm that whole table items will be left for the table to pay
Complete Guest 2’s payment
Guest 1 can continue to add items to their order
NOTE
If you tap Pay for Items or Pay before tapping Leave Table, Guest 2 can still pay for their items but no further items may be added for any guest at this table.
Reference Site: https://help.clover.com/faq/if-guest-1-stays-and-guest-2-leaves-how-can-i-allow-guest-1-to-continue-adding-items-to-their-order-while-taking-payment-from-guest-2-tables-app/