I'm afraid the search for member feature won't help to identify members from the staff positions, not unless you know their usernames already. Knowing their usernames means, you already know their positions as well.
You can try to see how it can work, until it was disabled.
I try it seconds ago, and I confirm that still works well today.
Admin
Cyrus
theymos
Staff
EFS
Welsh
sapta
Halab
dbshck
xandry
HostFat
Adriano
Igebotz
Xal0lex
gmaxwell
Mitchell
achow101
Barcode_
mole0815
OmegaStarScream
It seems the list is short.
The thread you've created is the best way to take a look whos who on the staff ranks/positions, kudos to it.
I am happy to know that it is helpful.