You can do that by exposing the Payment Status column from More > Show/Hide Columns on the Vendor Bills screen. You can also filter the Vendor Bills screen on Payment Status and select the options Paid or Partially Paid under it, as needed. When you apply the filter, CORE displays only the vendor bills that have payments made against them in full (Paid) or in part (Partially Paid). Check CORE Help Center for details on applying filters in the Vendor Bills screen.
Note: You can also use the Vendor Bills Paid report for this purpose.