is there only one place per GC for GC Leves?

[JMadFour]

Flames is in Drybone, Adder at Hawthorne Hut, Maelstrom i forgot.

But are those the ONLY places to get GC leves in the entire game world?

[Lazearus]

Whitebrim (Coerthas) and Saint Coinach's Find (Mor Dhona) each has a GC leve npc containing leves of all 3 GCs.

[Estellios]

In case you didn't know, it's also worth mentioning that you can also do other companies' gc leves for (I believe) a reduced reward.

[Dark_Legacy]

Flames is in Drybone, Adder at Hawthorne Hut, Maelstrom i forgot.

But are those the ONLY places to get GC leves in the entire game world?

The ones you listed are the lvl 20-24 and 25-29 leves. For 30-34 Adder is south shroud camp tranquil, flames is south than little ala Mihgo, Maelstrom is east nosca at costa del sol. 35-39 all three coerthas at the observatorium. 40-44 all three coerthas whitebrim and 45-49 mor dohna at saint conachs find.

[Spawnie]

theres multiple places that the npcs have all the GC leves 2 i can think of atm are coethas and mordhona xD