With the current situation, i.e. CX's suspension of flights to/from HKG, there's no way to originate a xONEx in Sri Lanka/CMB.

The problem is that you can get out of CMB on RJ to AMM, but you cannot fly back to your point of origin without breaking the rules. You would require a second entry into Europe and a backtracking between continents (e.g. CMB-AMM-other Europe/ME-North America-Asia-AMM-CMB) or a final international land segment within Asia. Both these options are clearly out of discussion. Thus, until CMB is connected by oneworld carriers to some other Asian destination, xONEx ex-CMB are not to be booked.