Question

I want user to view by recent Post in the order they were posted, but only if the user that created the post gave the user permission to view them. Much like google+ circle list.

Here is my original design, any suggestion on improvement, would be appreciated.

USER
Id
Name
...


POST
Id
Message
IsCloseFriendCanView
IsFamilyCanView
IsAcquaintanceCanView
IsDisabledComment
IsPostLock
CreatedByUserId
Created_Time
LastComment_Time 
...

POST_COMMENT
Id
PostId
Message
CreatedByUserId
Created_Time


FRIEND
Id
UserId
FriendUserId
IsCloseFriend
IsFamily
IsAcquaintance
IsBlocked
....

FRIEND_LIST (custom friends list only)
Id
UserId (owner)
FriendId
FriendListTypeId

FRIEND_LIST_TYPE 
Id
UserId
Name
...

POST_FRIEND (CAN VIEW)
Id
PostId
FriendId
....


POST_FRIEND_LIST (CAN VIEW - custom)
Id
PostId
FriendListTypeId
....

EDIT: updated

Answer 1

Not sure if this is what you want but seems you will also need a table holding the relation between user and friends

e.g.

FRIEND
user_id
friend_id
close_friend

And on POST you would need something to identify whether it is visible to “All Friends”,”Close Friends” or “Public”.

Then assuming $this_user is a logged in user or some dummy value e.g. -1 if not logged in, you can select a list of valid posts which will show

1. posts created by the logged in user
2. posts created by friends of the logged in user visible to all friends
3. posts created by friends of the logged in user visible to close friends
4. posts set as public

using something like

select p.id, p.message, 
  from POST p
 where createdbyuserid=$this_user 
    or (visible='F' 
        and exists (select 1 
                 from friend f 
                where p.createdbyuserid=f.user_id 
                  and f.friend_id=$this_user)
       )
    or (visible='C' 
        and exists (select 1 
                 from friend f 
                where p.createdbyuserid=f.user_id 
                  and f.friend_id=$this_user
                  and f.close_friend='Y')
       )
    or (visible='P')
 order by created_time

If no user is logged in, then $this_user would be set to -1 so only the public posts would be visible.

Then you use the result from this select to get the relevant comments for each post in a subsequent select.