For one of my addons I use this function. It does not return the "old" values. So you need to find the right values for your addon.
Lua Code:
local function getContinent()
local mapID = C_Map.GetBestMapForUnit("player")
if(mapID) then
local info = C_Map.GetMapInfo(mapID)
if(info) then
while(info['mapType'] and info['mapType'] > 2) do
info = C_Map.GetMapInfo(info['parentMapID'])
end
if(info['mapType'] == 2) then
return info['mapID']
end
end
end
end