How to show "Custom" instead of friends' name on facebook?

[chun02160]

I recently found out that when I share my post with certain friends, it apparently shows their names of whom I shared with. I checked it with my another facebook account. The thing is that even if I make my friend list viewable to "only me", meaning my friends' cannot see except mutual friends, it still shows the list of individual names of whom I shared with, both mutual and not-mutual friends. I want to show it as "custom", not list of the names. I usually do Post Privacy setting -> Custom -> select list of name I want to share with. Can anyone help me how to show "custom"?

[Edson]

This link has several tutorials for Facebook: http://www.trafegoweb.com/2013/05/tutori...ebook.html