Get books in a series in Books on Mac
You can view an entire book series, purchase the next book to continue where you left off, and view recommended series.
In the Books app
on your Mac, click Books (or another collection) in the sidebar.Books that are part of the same series appear in a stack.
Double-click the series stack, then do any of the following:
Buy an item from the series: Click the price, enter your Apple ID, then click Buy.
Download a purchased item: Click the iCloud status icon
to the right of the item.Open a purchased item: Double-click the item.
View the full description for an unpurchased item: Double-click the item.
View similar series: Scroll to the bottom.
Choose the order items are listed in: Click the More button
in the upper-right corner, then choose an option under “Sort by.”Choose which items to view: Click the More button
in the upper-right corner, then choose All in Series, Purchases, or Not Finished.
To share a series, click the More button 
below the series stack, then choose Share Series.