Just put it in the parameters.
function V(du, u, _p, t)
p, Rate = _p
du[1] = Rate(t)
du[2] = p[1]*u[1] + (Rate(t) / u[1]) *u[2]
end
p0 = [1.]
u0 = [1.0, 0.2]
N = 8
prob = ODEProblem(V, u0, (0., 12.), p0)
function prob_func(prob, i , repeat)
Rate = ConstantInterpolation(y[i], x[i], extrapolate=true)
tspan = (tspan_data[i][1], tspan_data[i][2])
remake(prob; u0 = initial_conditions[i], tspan = (tspan_data[i][1], tspan_data[i][2]), p = (prob.p, Rate))
end
enprob = EnsembleProblem(prob, prob_func = prob_func)
sim = solve(enprob, Tsit5(), trajectories = N)