ORD-ORF (AA)
BEG-BER (W6, JU)
BER-HER (U2)
JOS-LOS (W3 (Arik Air))
LIS-LYS (TP)
And a questionable one: MAH-MLH on U2. Questionable, because BSL seems to be the more usual code for Basel Mulhouse airport.
While I think that the "last two letters" requirement is a bit restrictive, it's one of the fundamental rules designated by the OP.