In the top nav bar, click on the "Profile" dropdown. It will expand.
Click on the ( Menu) icon on the top right corner of the page. The menu will expand.
Then click on the dropdown that says "My Profile". It will expand.
Then click on Edit Settings in the list of links.
Then click on Edit Block Settings in the list of links.
Then select the criteria of members that you want to block (by Location, Age Range, Gender, Marital Status, etc.). Then click the "Save Changes" button.