Functionality has been added to enable the linking of site services. When an active service is added to, or already exists on an account, supplementary services like a "locking bar" can be included and associated with it. Upon linking services, a parent/child hierarchy is formed, with the "child" service code referencing the Service ID of the corresponding "parent" service code.
Further documentation, including setup requirements and logic can be found here: Site Service Linking
Pathway: Accounts > Customer Service Screen > Active Services; Setup > Services > Service Code