The entire Scottish Clan Galbraith has members who were Clan Chief, but that is not denoted on the few profiles that I have had a chance to peruse. I will be working to resolve this on the ones that I can access - starting from the top, they are 13th century profiles, though. The most recent Clan Chief was the 19th - James Galbraith - whose term was up before the turn of the 18th century. So clearly, not all of them are out of reach.
If I recall correctly, e.g., "2nd Clan Chief Galbraith" is appropriate to enter into the Nickname field. I have to make myself a short checklist so that I am certain to add those who are not on the Clan Galbraith site, already.
By the way, I am in the process of confirming my management of the Clan Galbraith site, here.
Föhn Foehn of the Marshy Bog Leewards and the Slippery Alleles