The Spaces tab provides an innovative feature to define areas within the PDF that makes storing and sorting markups easier and more efficient.
Go to View > Tabs > Spaces or press ALT+S to show the Spaces tab.
The Spaces tab toolbar contains tools for adding, editing, manipulating, and deleting Spaces.
Expand All: Expands all pages and nested areas to show all the Spaces defined in the document.
Collapse All: Collapses all pages and nested areas to show only the page labels.
Highlight Spaces: Toggles between showing and hiding existing Spaces.
Edit Spaces: Allows resizing and other editing of existing Spaces.
Add Space: Creates a new space.
Cut: Cuts the selected Space.
Copy: Copies the selected Space.
Paste: Pastes a cut or copied Space.
Delete Space: Deletes the selected Space.
Space Properties: Allows you to change the Properties of a Space.
Working with Spaces