This is a two-control treble-and-bass tone stack fed, like its three-knob sibling, from a cathode follower. The follower's low output impedance drives the passive network, and two interacting controls set treble and bass independently — one knob short of the full FMV stack, one knob past the single tweed tone control.
It marks the point where Fender's larger tweeds outgrew a single tone knob but hadn't yet reached the three-band stack. Keeping the cathode follower means the tone network can be as lossy as good control range requires without loading down the gain stage ahead of it — the same reasoning that makes the FMV arrangement work.
For where a stage like this falls in the signal path, the guide to reading a schematic walks the coupling between stages. The plainer relatives — a single tone control and no tone stack at all — are documented alongside.