Steps to implement the above scenario:
1. Create a new Organizational view, and move those machines in the view (Group A which you need to manage with Limitedadmin1).
2. Create a Role (name Test) and go to the security role manager for that role.
3. Select Resources and add the specific Organizational Group to the role (as shown next). Give the required permissions.
4. Assign the role to the user (Limitedadmin1) as shown next and also assign the privileges for the console which you would like the user to access.
5. Open the console with the user (Limitedadmin1) and it will only show you the machines for the Specific Organizational Group for the one you have created the role (test).