When you create
a homegroup, you select the libraries and printers you want to share with other people in the homegroup. Selected Libraries are set to be shared with Read
only access by default, which means that you can look at or listen to what's in the library, but you can't make changes to the files in it unless this is changed by the owner of the shared library to allow the homegroup to be able to do.
When you join a homegroup, all user accounts, except the Guest account, on your computer become members of the homegroup. Each user controls access to his or her own libraries.
This will show you how to change your user account's library files and folders level of access settings for how you specifically want them to be allowed or prevented for sharing with the homegroup.