BPEL - Get a value from array of element in a loop.

In a loop, the counter is a incremental value with the loop.

Directly use the variable to get the value of specific postion in the array in BPEL 2.0.
$inputVariable.payload/client:input[$counter]

Use XML manipulatioin in BPEL2.0.
ora:getElement('inputVariable', 'payload', '/client:process/client:input', $counter)