Custom Access Permissions I need to build a facebook model privacy settings for user. Access permissions must be set to users who are "Public" and "Connected", which the latter is from User Relationship module. 

eg: User must have permission settings such as who must view his profile, his nodes, user connections, also some views which are related to user.

Can anyone suggest an idea how can i implement this.
Just use the Group module, and create a content type like "Connected Users". And then create a "group" for each user (using something like the user's name as its label), of group type "Connected Users".

Tune the permissions which come with the Group module (which are different from standard Drupal permissions!) to fit your needs.

Possibly you also want to use all sorts of integrations with modules such as the Rules module or the Views module (the Group module is entirely entity based, so those kind of integrations or virtually unlimited).

Voilà ...

PS: This answer applies for either Drupal 7, or Drupal 8.