Facebook lets you decide who sees what you post on your wall. It does this through privacy preferences. If you go to the menu with the three horizontal lines, you will find the Privacy shortcuts button.
Privacy shortcutsAmong the various options is Review a few important privacy settings. Tap on it to see more privacy settings.
Since the goal is to control who sees what you share, tap on Who can see what your share.
Who can see what you shareTap Continue to start the privacy wizard.
Privacy assistantFirst, you have choices regarding your personal information. Adjust these parameters if necessary. To continue, tap on Next:
Control personal informationIn the Future posts section, tap on Friends, this is the default option.
Configure who can view your publicationsSelect who will be able to view your posts from now on.
Privacy options availableRepeat the process with Facebook stories tapping on Stories. Similarly, if you want to apply the same restrictions to your previous posts, tap on Limit.
Limit old publicationsConfirm this last change by tapping on Limit again.
Confirm limitationThe final step of the wizard will let you block some users. To finish, tap on Next.
Block usersWith this method, you will have modified the default settings of everything you share. However, you have privacy control in the post editor.
Control who can view a specific publicationIf you change this setting, the setting will only apply to that particular post. The default settings will remain the ones you chose in the privacy wizard.