Given an Azure Service Bus to which I have access and in which I can see all queues, topics, and topic subscriptions, is there an easy way in which I can see all subscriptions forwarding messages to a given queue?
Is my only recourse to write code which will iterate through all of the topics' subscriptions in the Service Bus and compare the "Forward To" setting to see if it matches the queue to which I'm interested in?
Out of the box, there's no functionality you're asking for. You will need to write custom code to achieve that. You could also raise a feature request with the broker team.