I’m not sure if I misunderstand your data and if this solution is plain wrong, but have a look:
using GLMakie
GLMakie.activate!()
ts = 1:10
data = [rand(10,10,10,10,10,10) for t in ts]
i = Observable(1)
f = Figure()
data_1 = @lift(data[$i][:, :, :, 1, 1, 1])
data_2 = @lift(data[$i][1, 1, 1, :, :, :])
volume(f[1, 1], data_1, axis = (;type = Axis3))
volume(f[1, 2], data_2, axis = (;type = Axis3))
ls = labelslider!(f, "t", ts)
f[2, 1:2] = ls.layout
connect!(i, ls.slider.value)
f
