Assigning different GameMode BP to different maps?

Totally confused again, when each map is loaded in my project, they always use the default GameMode.
So how do I assign different GameMode Blueprint to different maps?

ps. Is all the blueprint persistence between level loading? If I load a new map, how do I know which Blueprint and actor stay and go?


Never mind, it’s under world setting… not so world after all I guess. Should rename it to map setting or something…