ruled-switch-buffer

This library provides a macro to define rules for moving between
related buffers, and a command to switch between buffers according
to the defined rules.

An example of a switching rule is a rule to switch between .c and
.h file.  Once you have defined such a rule, you will be able to
quickly switch between .c and .h.

You have to define the rules yourself.  This library does not
provide any specific rules.