looking to manage data access for a single app with authentication

I want to know is there any possibilities to manage a single Shiny App with different login permissions.

I have Tab 1 in my App and this Tab includes two more subtabs
Tab 1:1 and Tab 1:2.
I have users A, B & C who are accessing the Tab. But I want to give access to Tab 1:1 to user A only, Tab 1:2 to user B and access to the whole tab to user C.

Is there any solution to this?

Aneeta, how are you hosting your application. If you are using Shiny Server Pro or RStudio Connect the username is available as session$user and can be used for conditionally showing parts of the app. For example: http://shiny.rstudio.com/gallery/personalized-ui.html