When you want to add someone you need to click on the bottom "Add As a friend" then there will be a drop down box, choose "more list" and select "restricted", they will then only see the content you made public.
But you need to go to your privacy setting and define which content can be seen by different lists.
The access level of your friends are being determined by LISTS which you can modify/add/ delete them easily. how?
Find LISTS in the left side of HOME(Not your profile) and then there is a pen next to it with which you can edit them, when you get into the LISTS categories, you can edit them by clicking on the same pen on their left side, easily categorize your friends by adding them to relative list.
You also can see RESTRICTED list members.
When you are sharing a content you can see an option letting you to decide to which list(s) your content will be shown.
If you need more assistance please writ here.
Good luck