Improved search API for shared numbers

Feature Request Summary

We need an improved search API that can help distinguish "direct line" and secondary phone fields. This should allow us/partners to build more solid solutions that can handle shared user numbers.

Use Case

The issue is that when we have multiple requestors that are calling in via Amazon Connect that have the same telephone number. Our voice integration (by Voicefoundry/TTEC) allows for the customers requestor account to be popped to the screen with open tickets, but this is causing issues with requestors that share the same telephone number, for example a hospital department or office that has multiple requestors but they dial out from one phone number. ZD has clarified that they cannot resolve this OOTB (see Why are some users not correctly identified when they call in? – Zendesk help). Shared numbers are possible in ZD but the calls will always be associated with the user that has the number put the "direct line" originally. ZD's solution is to just change the requestor when someone new dials in. That requires due diligence for agents to ensure they speak with the right person with the risk of mixing up requestors and tickets.

Product limitation or missing feature

The root cause to this issue seems to be the lack of a solid search API that can pull the list of users with the same shared number incl “direct line” and secondary numbers. 

Business impact of limitation or missing feature

With this limitation we are bound to have human errors when we manually have to identify that this is the wrong requester. The workaround in the above linked article will not suffice for us.