Combine Subscriptions

It would be very helpful if you could combine subscriptions for the same customer. For example, if a customer has booked a new subscription before the old one has ended, it would be more convenient if they could have the two subscriptions combine instead of having to search the emails to know which one has which subscriptions. I had customers take advantage of a sale and purchase new subscriptions before their old ones finished and now it is a bit inconvenient for them.