Do you mean for the classic profession level progress bar?
For the full window, see Wow_CqWTJFEMt5.png file, it will be Dragon Isles. Do the following to change:
- Go to Professions (k)
- Click the Profession
- Click Filter
- Click the profession type you want, i.e Classic
That will show the current profession level but it is not permanent, the filter will reset when you /reload
/ exit game / log out / log back in. It will reset to the highest expac profession learned, for me it will be Dragon Isles.
After logging on to a level 24 character and learning professions esp classic, any addons or weak auras that display professions level bars will show the highest expac profession, so, if you learned Classic <name of profession> and then learned Outland <name of profession>, Outland will now show in the bar. This is regardless if you learned 300/300 or 75/75 of the previous one.