You’d b better off disabling the buddybar and customizing the wordpress bar. There’s lots on the web about that, and the buddy bar is slated to go away, I believe.
Add this line to wp-config.php to re-enable the WP bar:
`define ( ‘BP_USE_WP_ADMIN_BAR’, true );`
Actually, I think you should add that to /plugins/bp-custom.php (would work anyway)
@MaTaX91 as @dcavins said, the buddybar is being depreciated (when BP 1.6 comes out) so, you should use the toolbar.
The toolbar is alot easier to modify too 
Here’s the codex – https://codex.wordpress.org/Function_Reference/add_node