I understand that there is no native report or tool on the platform to perform this task. In what way can I solve the requirement, through a development? Any idea or suggestion?
The IVR reporting feature is currently in limited release, with the GA release tentatively scheduled for this quarter (keep an eye on the release notes). If you cannot wait, you will need to develop your own solution to log the information you want and send it to some external system. This will probably involve some combination of participant attributes and data actions and a custom external application to receive the data.
We had success simply putting in Wrap Up Code actions in the inbound call flow for each option step, they get appended to the interactions and you can pull that info via the API. Use PowerBI to slice it and you've got your stats.
So for your example, you could have a wrap up code Option 1.1 and then another one for Option 1.1.1 and another for Option 1.1.2.
So the interaction would have the following wrap up code after the customer spoke to an agent.