Ideally, basking & UVB lighting should intersect, and their should be gradients of both/either, so your cham can decide where s/he wants to be—and be able to get to those places.
That said, neither type of lighting is likely to be used by your cham
all the time
every day. Again, they know what they need or want, and will seek it out.
I spent
days setting up what I thought would be the perfect basking area, with proper temperatures, RH, gradients, some shade, ventillation, water availability... and the little bastard has yet to set foot in that area at all. Instead, he climbs around it, gets closer to & farther from both lights, walks across—and hangs out on—the ceiling with either or both lights shining on his little belly, and spends a lot of time hiding in the tops of a mass cane or ficus, ignoring the gorgeous schefflera in the middle.

Go figure.