In order to display a break down of the different sub-items comprised into a service composed item, use the convert to group button of the composed item as shown in the tutorial video below!
Important: Since the total sell value of the Composed Item is manually assigned by the user, based on the sum of the individual sell prices of the sub-items incorporated in it, once you convert a composed item to group, you would need to adjust the individual sub-item prices, one by one to match the desired total value!