Multi-level IVR trees are frustrating for a customer.
While it might be tempting to specialise your team as much as possible, try to avoid it if it comes at the expense of the customer experience.
It can also be costly for your team because it increases the number of transfers required if your team is super-specialised.
Pro-tip: You won't need dozens of IVR tree branches if your team is well-versed in all customer questions.
Here is an excellent article about that by Octopus and BCG.