You have some information about your family in Family Tree. Your spouse has information about his family. Your cousin has also added stuff. All of you just want to be able to see all of it. Why can't you?
You can--and you can't.
Records of living people are protected. You can add records for your living relatives. So can your spouse, and your cousin, and your children, and your parents.... But each of you has to add your own record of those living relatives in what Family Tree calls your Private Space. And therein lies the problem.
For most of us, at least some of our progenitors are still living. So, to be able to see all the family tree stuff another family member has put in Family Tree, we first need to create the living links back to our first deceased common ancestors.
For example, suppose my Aunt Mary has added a lot of information about my father's side of the family. But I'm not seeing those people linked to my part of the tree. My father is living and I'm sure she has him in Family Tree. But when I search for him, I can't find him. That is because he is living. If Aunt Mary has created a record for him, it shows in her Private Space. She is the only one who can see that record. Here's the solution:
I need to create a record for my father. I go to myself in the tree--that should be simple to find, since I'm in the center of the tree when I sign in. I click my name on the tree and then click my name again on the summary card that pops up.
Notice that Private Person banner at the top of the details screen? I am living--my record is protected from viewing by others. I scroll to Family Members (sorry--no screen shots this time. I don't want to publish records of the living). If I do not yet have a record for my father, I click Add Parent in the right column of Family Members--under the PARENTS AND SIBLINGS heading.
I enter his information: name, sex, that he is living, birth date and place. Then click Next. (You might be tempted to ask Aunt Mary for the ID of her copy of my father and then click that handy Find by ID link. But, it won't work. You can't search by ID for living people unless you created the record.)
Click Add New to add him as my father. While I'm at it I might as well add my mother too and their marriage info.
Since I'm trying to find the stuff Aunt Mary added, I next need to add my father's parents. So, I'll click his name in the PARENTS AND SIBLINGS section and then click his name again on the summary card. Repeat the same steps I used to add my father--add his father and his mother in the Family Members section.
Repeat this process until I have all the living generations added. Then I should be able to search for the first deceased ancestor and find the existing record--hopefully the one Aunt Mary added. If Aunt Mary is extra nice and wants to help you out, she can give you the Family Tree ID of your deceased great-grandparents so you can find the record she created and added all those nifty photos and documents and sources too. And suddenly the tree bursts into bloom before your eyes.
Obviously, the process is the same to see a spouse's ancestors. Add your spouse, if you don't already see him. Add any living progenitors for him and then search for the first deceased ancestor. Again, you could ask him for the Family Tree ID of the his first deceased generations so that you can find by ID and save some typing.
And, since I know that you are wondering what happens to all those copies of currently living people when they die, I'll tell you. Suppose my father is living (which, in fact, he is). I have a copy of him. My husband has a copy of him. Each of my 5 children have copies of him. Their spouses have copies of him. My cousin has a copy of him.... You get the idea. When he dies, if each person who has a copy of him in their Private Space adds his death information, all of those records become public--and duplicate records. So, somebody needs to go find the duplicates and merge them into one record.
I am not sure how FamilySearch.org is handling exact duplicates these days. There was a time when the system would automatically merge those duplicates when the death info was added. And perhaps it still does. My mother died in 2013 and I added her death info. I have not yet found any duplicates of her, and I know that several other family members created records for her. But I don't know if that is because FamilySearch.org merged the exact duplicates or if other family members haven't added her death info.
Bottom line--you can see information others have added to Family Tree, but you have to do a little leg work first and add in your living family members to provide that link to the deceased generations.