I’m not clear quite what you want but the end of the following post is about creating different logged in and out menus ( with a child of bp-default theme ) …
https://buddypress.org/community/groups/how-to-and-troubleshooting/forum/topic/how-do-i-make-buddypress-1-6-a-private-community/#post-136021.
to @amitsingh1984: well whichever file, your menu’s code is located in then add this code at before the menu’s script: <?php if (is_user_logged_in()) > and make sure at the end of the script for the navigation you would include this would take that whole chunk of script for your navigation and shows if the user is logged in or you might also use Sara Goodings plugin “if-menu” but I would suggest the code since it takes less time for your site to load.