I wish to use neo4j to handle relationship among customers.

How do i get mutual buddies utilizing it?

The simplest way is always to make use of the least path formula of length 2, using the two customers, across FRIEND_OF associations. Individuals would be the pathways that connect the 2 customers via exactly one friend hop.

PathFinder<Path> finder = GraphAlgoFactory.shortestPath(
        Traversal.expanderForTypes( FRIEND_OF ), 2 );
Iterable<Path> paths = finder.findAllPaths( user1, user2 );