We can do this through our extension in the following ways –

We create a warehouse attribute. In this warehouse attribute, we create various options like warehouse A, warehouse B and warehouse C. This warehouse attribute is assigned to our used attribute set. We create products and assigned a requisite warehouse. Now a customer has placed an order with 5 products

a. Product A belongs to Warehouse B
b. Product B belongs to Warehouse A
c. Product C belongs to Warehouse A
d. Product D belongs to Warehouse C
e. Product E belongs to none of the warehouses

In this case, our order will be split into 4 different orders –

a. Order 1 having products of warehouse A, i.e Product B and C
b. Order 2 having the product of warehouse B, i.e Product A
c. Order 3 having the product of warehouse C, i..e Product D
d. Order 4 will be of none of the warehouses, i.e Product E

Note – Split Order On Checkout will work with the Magento default payment methods that are Cheque / Money Order and Cash on Delivery. In the case of any 3rd party payment gateway, it may need some customization if the third party payment gateway code does not follow the default Magento payment module pattern.