Not sure what you're asking for.
Are you asking where msaccess.exe is located? Syscmd(acSysCmdAccessDir) will
give you that.
Are you asking where the open mdb file is located? CurrentProject.Path will
give you that, or you can parse it from CurrentDb().Name.
Are you asking what the current directory is? CurDir will give you that.
Next time, please put your question in the body of your post. That gives you
the ability to be more explicit in what you're asking.