Chimera kagune

in rare cases a ghoul will inherit their kagune from both parents, instead of just from one. The first ghoul shown wielding dual kagune was Hinami Fueguchi, who possesed a koukaku, from her mother, and rinkaku, from her father. The only other ghoul who's shown to have one is the nutcracker ghoul who possesses a bikaku and a koukaku.

as shown by nutcracker a ghoul with dual kagune can activate one at at a time, or both.