So, my app has multiple Roles and each Role has a set of Users.
I want to create a drop down field which will have choices of Users within a specific Role. How do I achieve that?
I assume you mean the actual users assigned under the 'Users' and not a table of roles and users that you setup yourself? For Application roles and the associated user in that role you'll have to sync the Application User data into a new table using Pipelines and the API. There isn't a native functionality that grabs users and what role they're in within an application. I'd suggest taking a look at API_UserRoles and API_GetRoleInfo as the combination of those (2) calls will get you the roles in the app and users in each role.
