Before you proceed, you need Spaces installed on your phone.
How to change the visibility of a Tab?
Step 1 - Open the Space for which you want to change the visibility of a tab and Navigate to the Tab.
Step 2 - Click on the name of the tab.
Step 3 - You can see the information about the Tab. Click on the Settings icon.
Step 4 - It would open up a pop-up screen, choose as per your requirements, be viewed by only the Admins, Members, Anyone and Click on the Save button.
You are done!