The Cumans, primary antagonists in the first game, reappear in Kingdom Come: Deliverance 2, initially within a side quest titled "Invaders." This guide details how to locate their camp.
Initiating the "Invaders" Quest:
Early in Kingdom Come: Deliverance 2, after a couple of in-game days following your separation from Hans Capon, return to the Troskowitz inn. Speak with the innkeeper; she'll mention the Cumans' unsettling presence and request your assistance in serving them.
This starts the "Invaders" quest. Your choice to serve or refuse the Cumans will influence events, ultimately leading to a conflict between them and the townsfolk. Your dialogue choices will determine which side you must support. Regardless of the outcome, the Cumans will depart, prompting Vuytek to enlist your help in preventing their return to Troskowitz.
Locating the Cumans' Camp:
To find the camp, begin by gathering information in Semine, located southwest of Troskowitz. Speak with Lord Semine to learn more about the Cuman whereabouts.
The Cumans' Camp is situated southwest of the Nomads' Camp, itself west of Zhelejov. The map screenshot below pinpoints its exact location.

During daylight hours, you can traverse the Nomads' Camp and follow a downward path leading to the Cumans' Camp. Interact with the Cumans there to advance the quest.
This concludes the guide on finding the Cumans' Camp and completing the "Invaders" side quest in Kingdom Come: Deliverance 2. For more game tips and information, consult The Escapist.