Where to go after first time meeting The Hunter?

[Arey Vermillion]

Head back to base and do missions for Daivs, or there's some hidden way there?

[㊈ y u w e i]

You gotta go back to the Ruined City Center, at the mistle at the parking garage.
From there, go down, follow the path until you have to choose from two directions, take the left and go down the pit by jumping on the platforms, you'll reach the next area.

[Moka]

go to ruined city center, find the giant pit, ride the elevator, follow the cave.