Dear Cathy,
Few metrics like Entries, Exits, Bounces(Single Page Visits) etc., are captured once in a visit and they have a visit breakdown scope, which means they persist through out the Visit.
For example, if a segment has the following condition: Page equals A on a Hit container.
Say, a visit has the following sequence of pages: A -> B -> C -> D. So, the Exit page was D, in this case.
Now, when you select Exits as the metrics, D will appear in the list even through the hit segment only has A.
That is the reason you cannot find these metrics even in the segmentation listing.
So ignore the line items which didnt have hits and continue.
Thank You!
Arun