In each of the centre-assessed units you will find a specific requirement for candidates to evidence synoptic learning in one of the marking criteria.
This will often refer back to the examined unit within the qualification – although sometimes might not. The statement in the marking criteria states “Draws upon some relevant skills/knowledge/ understanding from other units in the specification.”
Candidates should ideally make an explicit statement of how the work they are performing is informed by work done in other units. A simple statement where appropriate will suffice.