Each book has a listing in the middle scrolling window at the left of the current database display. [The topic listing for The Civil War CD-ROM is shown here but the concepts are the same regardless of the particular product you have.]
Clicking on the [+] sign (a swiveling arrowhead on the Mac) expandor next to "Army Official Records (128 volumes)", and then onto the expandor next to the "AOR -- Series I (Battle reports)" will display each serial numbered book in the series:
Then, clicking once (not double clicking) on "S#1 (Vol I)" will show:
Double clicking on " '60-12-20:Ops. in Charleston Harbor ...":
will then cause the right hand topic window to display that topic, as such: