Hrm, I'm assuming all flight segments must be direct in this case? There was a day where only connection is available from TPE-TYO and website shows HKG/FUK/KIX as connection points but all turned out to error after selecting.
Please read the rule carefully.
Your final itinerary determines validity.
Selected flight(s) are only a candidate. Because of routing restriction can be determined based on only finalized itinerary.
You can include only two stopovers, including one in the destination.
You can include maximum two transfer points in outbound, maximum two transfer points in inbound.
You can't go through the origin.
HKG-TPE-xKIX-HND-HKG : valid
HKG-TPE-xKIX-HND-xFUK-HKG: valid
HKG-TPE-xHKG-HND-HKG: invalid
HKG-TPE-xICN-xFUK-HND-xICN-xTPE-HKG: invalid