refer-bib-directory

refer-bib-directory is a variable defined in `refer.el'.
Its value is

nil

• Automatically becomes buffer-local when set.

Documentation:
Directory, or list of directories, to search for \.bib files.
Can be set to 'bibinputs or 'texinputs, in which case the environment
variable BIBINPUTS or TEXINPUTS, respectively, is used to obtain a
list of directories. Useful only if `refer-bib-files' is set to 'dir or
a list of file names (without directory). A value of nil indicates the
current working directory.

If `refer-bib-directory' is 'bibinputs or 'texinputs, it is setq'd to
the appropriate list of directories when it is first used.

Note that an empty directory is interpreted by BibTeX as indicating
the default search path. Since Refer does not know that default path,
it cannot search it. Include that path explicitly in your BIBINPUTS
environment if you really want it searched (which is not likely to
happen anyway).

You can customize this variable.