To set permissions on a page, you first need to go to the Permission Settings tab via different ways:
Via Edit Page:
Hover your cursor over My Sites on the Administration bar, then select the page you want to configure from the drop-down menu.
You will be directed to your selected site.
Continue hovering your cursor over Edit on the Administration bar, then select Page --> Layout from the drop-down menu.
Click View Page Properties in the Page Editor window.
Select the Permission Settings tab.
Via Page Management:
Hover your cursor over
on the Administration bar, and select
Portal --> Pages
to open the
Pages Management
page.
Locate the page you want to edit using the Page Id column, then click
corresponding the page in the Action column. You will be taken to the Page Editor window.
Select the Permission Settings tab.