How to bind java function name to webservice list input of CAF page

I have created a java function to return selected rows of an async table. Now, I need to bind this function as input to another webservice (created by flow service) in CAF page which is same as selected rows of async table. Please advise how to bind a function name to input list.

Example :

GetCustomer is a function I wrote in java class. This will return a list of selected rows in async table. (Document name is Customer). In customer document I have “Name”, “Age” as fields. I want to send the list of Customer document retrieved from GetCustomer function as input to another webservice “Delete Customer”. It takes list of customer document as input. Please advice how I can bind my GetCustomer function name as input to Customer list document of “Delete Customer” service.