Do you mena the panel itself is missing, or that the panel is blank, or that you've hidden the hyperlinks half by adjusting the window split?
Have you tried resetting the workspace?
The hyperlinks panel is missing. All I can see is cross-references. I can't get the split window to bring back the hyperlinks section. I've tried resetting the workspace but unfortunately that did not work.
I don't don't know if you ever resolved this but I had the same problem and the only advice I had was to trash preferences, which didn't work for me either.
In the end, I found a far easier and effective way to reset prferences:
Quit Indesign then while holding down Shift, Ctrl, Alt, Cmd, open Indesign. You'll get a preference reset option, click 'yes' and hey presto, Hyperlinks is back.
Best of luck