Select Vendor Bills with multiple Vendors WHERE Vendor Bills's Status must be open.
Click on Register Payment for Multiple Vendors/Customers.
It will open a Pop-Up with selected vendor bill's Information.

Explanations:

Payment Journal : User select a Journal.
Payment Date : Today's date by default. User can change it.
Selected Partners : User can see list of Unique Vendors/Customers which selected for Mass-Registering Payments. Its Readonly field.
Wizard Lines will show Invoices Sort By Vendor/Customer of Vendor-Bill/Customer-Invoice From selected Invoices.

Details of Invoices:

Partner : Vendor-Name/Customer-Name.
Number : Number of invoice.
Due Date : Due Date of related Vendor-Bill/Customer-Invoice.
Invoice Amount : Total amount of related Vendor-Bill/Customer-Invoice.
Amount Due : Due Amount of related Vendor-Bill/Customer-Invoice.
Payment Method Type : By Default It will set Manual. Its editable So User can change it. e.g Check.
Payment Amount : It will set remaining payment amount of related Vendor-Bill/Customer-Invoice. Its editable So User can change it.
Memo : Reference Or Number of related Vendor-Bill/Customer-Invoice. Its editable So User can change it.
Validate Button: If Register payments for Vendor bills, Validate Button will create Vendor payments Group By Vendors and
         Payment Method Type.
         If Register payments for Customer invoices, Validate Button will create Customer payments Group By Customers and
         Payment Method Type.

Example:
    Here we selected vendor invoices of China Export,Delta PC,Camptocamp,ASUSTeK.
    After perform action Register Payment for Multiple Vendors/Customers, It will show Vendor-Bill Sort By Vendor. So use can easy see the invoice details.

    Here we can see 2 Vendor-Bill of China Export, 2 Vendor-Bill of Delta PC, 2 Vendor-Bill of Camptocamp
    and 4 Vendor-Bill of ASUSTeK.

    In BILL/2018/0001(ASUSTeK vendor), We selected Payment-Method-Type as Check.

    So Now when we Click Validate Button, 5 payments will create.
    China Export : 1 payment will create with 39.68 PaymentAmount. SUM(BILL/2018/0011, BILL/2018/0010)
    Delta PC     : 1 payment will create with 4,152.65 PaymentAmount. SUM(BILL/2018/0006, BILL/2018/0007)
    Camptocamp   : 1 payment will create with 109.26 PaymentAmount. SUM(BILL/2018/0009, BILL/2018/0008)

    For ASUSTeK vendor, we can see two different Payment-Method-Types So separate payments will create.
    1 payment will create with 10,000.00 PaymentAmount WHERE Payment-Method-Type = Check. SUM(BILL/2018/0001)
    1 payment will create with BILL/2018/0001 PaymentAmount WHERE Payment-Method-Type = Manual. SUM(BILL/2018/0004, BILL/2018/0005, BILL/2018/0003)