I feel like this is a very stupid question, but I don't see anything in either the customer or subscription REST API that covers it. Is there a call to get all subscriptions for a customer? As far as I can tell the list subscription call only allows filtering by plan, and the customer info doesn't seem to include their list of subscriptions.
To help anyone that probably visit this page again:
Yes, this is not mentioned on the Sample Code, but you will find it on the Input Parameters section below: https://apidocs.chargebee.com/docs/api/subscriptions#list_subscriptions_customer_id