To sync only certain branches from your main family tree, please do the following:
Open your tree in Family Tree Builder.
Go to ‘Sync (publishing)’ menu in the upper menu bar and select ‘Sync Settings’.
Click ’Advanced Settings‘.
Under ‘People to Upload’’ section choose ‘Specific people selected below’ and click on the ‘Select People’ button.
To add a person, highlight the name in the list and click ‘Select’. You will probably want to use the eldest ancestors in the tree to get a complete branch.
Now you will see the option to ‘Select People to Upload’:
You should see the name of the person you just added in the list. Clicking the ‘Edit’ button will allow you to include Ancestors, Descendants and Spouses, any combination of those three or the only the specific person.
You can add more people by clicking ‘Add’.
When you finish adding people for a particular branch, click OK to go back to the Sync Settings screen: