Hiding panels in a Layout Library page is a great way to customize your layout and make the necessary adjustments to ensure that your design looks just right. It's a powerful feature, as hiding/unhiding panels can create a create a different, more flexible page design.
How to hide a panel
Select the 'Layers' palette found at the top right-hand of your page.
Select the eye icon to hide a panel.
Once done, the eye icon will be greyed out and the panel will be hidden on the page.
How to un-hide a panel
Select the 'Layers' palette found at the top right-hand of your page.
Select the greyed out eye icon
Once done, the panel will no longer be hidden and you will be able to see it on the page.