The action returns a list of objects in the non persistent entity splititems.
This entity has 2 attributes, index and value. The value holds the string that you are looking for.
So splitting a string like A,B will result in 2 records in a list of splititems:
to access the data add a loop with the splititems list as input and work with the $iteratorsplititmes/value in the loop to access the string value.