Feature Request: Dependent Picklist Values

Feature Request Summary: 

Zendesk Support should allow picklist values to be filtered dependent on the selected value of another picklist in the ticket. 

Description/Use Cases: 

We have a picklist field called "Category" that has a long list of ticket categories (i.e. A - Z). We have a second picklist field called "Resolution" that has a long list of resolutions (i.e. 1-20).

Since many resolutions are specific to certain categories, the Zendesk admin should be able to set conditions to display certain picklist values based on what is selected in the "Category" picklist.

For example, if category "A" is selected, only resolutions 1 - 5 are selectable. If category "B" is selected, only resolutions 5, 6 and 10 are selectable. And so on.   

Business impact of limitation or missing feature:

This is important to reduce the amount of picklist values displayed to an agent, thus reducing the time it takes to select a value out of the displayed options. This is a huge timesaver that will help improve data integrity and streamline reporting.

Other necessary information or resources:

This is standard functionality in Salesforce and other ticketing systems. There are also several 3rd party apps that have accomplished this in Zendesk, but require a paid subscription:

https://www.zendesk.com/marketplace/apps/support/861234/hide-dropdown-values-app-by-leafworks/?queryID=2e6b125dfda92ef0b9b0a38b76151801