@Gaurav25 the use of Global Search is not mandatory, you can disable this on the Channel itself. Then you can just create your own landing page, that allows them to search the one case type they want. Blueprint Import does this natively for every case type you import, you get a landing page to view/search each case types. I prefer this option as then you can define other UX elements like what search filters they have and what columns/data they see. The Global Search View is not an authorable view, there are hacks to add more information to it but you never have full control here, as its not an authorable landing page. That said, you could play around with the search to try and exclude results, but you won't be able to hide "all" as an option, you might just be able to change what "all" returns.

• pySearchWorkParams – Set advanced work search parameters defined by users in the UI
• pyFilterSearchResults – Apply additional filtering after search results are returned