While Cloud Retailer is not a restaurant focused POS system, we do have some inbuilt features that let you work as though it is.
You can create an Order Type called a Tab through the Back Office
Click Admin on the left-hand side of the screen and select Order Types.
Then Create a new Order Type and Call it whatever you like.
Then once you have the Tab set up in the POS you can split it by Recalling the Order and selecting "Pickup" instead of "Select"
Pickup allows you to select the items and quantities for the items that the customer is paying for.
After you update the quantities of what the customer is paying for you can click finish and it will bring the transaction up on the screen with the quantities selected
You will notice that all items show on the transaction but the quantities will be 0 for those not being picked up. You can then Tender the transaction to separate payment types or Multiple cards and if your location accepts tips be able to apply a tip to each card used individually.