Looking at todays flights on the BA website
BA 73 LHR - AUH - MCT & vv
BA125 LHR - BAH - DOH & vv
BA137 LHR - FNA (Lungi Sierra Leone) - ROB (Monrovia)
There will doubtless be other flights like BA137 on other days of the week.
Not having a proper pdf timetable doesn't help but I can't think of any sector that does not start/end at a London airport or is a continuation of one.
I've often wondered who would want to fly one-stop to Muscat or Doha when there are non-stop alternatives available unless a lower fare was offered. Oman air has a single daily evening departure and BA must have significant transfer traffic to Muscat so it probably makes sense to extend BA125 there.
Now that Qatar has joined One World and offers five daily non stops to Doha you wonder how much high yield traffic attracts. Will BA end up serving DOH with codeshares sometime in the future?