From the documentation link here: https://www.gnu.org/software/emacs/manual/html_node/emacs/Other-GDB-Buffers.html
When gdb-many-windows is non-nil, the locals buffer shares its window with the registers buffer, just like breakpoints and threads buffers. To switch from one to the other, click with mouse-1 on the relevant button in the header line.
I am in the pure text-based terminal and don't have a mouse. Is there a built-in keyboard shortcut to switch between those two buffers (without having to add any extra configurations in init file)?
Either keyboard shortcut or command (like M-x ...) is preferred.