Originally Posted by
m3red
You need to do an advanced search and do
HKG DXB
DXB LYS
LYS HKG
assuming you want to stop on the outbound.
outbound would be HKG - LYS and OP had mentioned that's when he wants it. But yes, as m3red pointed out, do a multi-city/advanced search as:
HKG - DXB
DXB - LYS
LYS - HKG with the appropriate stopover dates.