Spawn in relation to other actors

No I have not! Why I should do this (and how…just create an empty AI controller blueprint and assign it to character blueprint?)
If I simple add the character (MyPassenger) in the level and add a node to move to a location, the character moves as expected (a default DetourAIController is assigned). The spawned characters are not moving with the above nodes in GM blueprint.
Nevertheless, i tried it (create an empty AI controller blueprint and assigned it to character BP) but nothing happened…

Sorry if I am missing something but as I said I am new in Unreal.
I really appreciate your help