Settings is in the upper right hand corner of your screen when you are in FamilySearch. Looks like a C. Click on this and a page will come up with different options. Select Contacts. A screen will come up and the last option on the screen is for enabling relationship viewing. Hope this is helpful, Carol
There are two ways that I know of:
One, as 'Carol' has already suggested is through your "Settings", under the "Contact" 'Tab', in 'FamilySearch'.
The other is when you select the "Contact Name" of a User/Patron who has contributed details to a record.
I hope this helps.