Add to /proc/self

No, you cannot add your structure in a meaningful way to /proc because it is generated (not a "real" filesystem). Likewise /sys on some machines. Changing the structure of /proc isn't straightforward (see for example Creating a folder under /proc and creating a entry under the folder).

Further reading:

• Linux Filesystem Hierarchy: Chapter 1. Linux Filesystem Hierarchy: 1.14. /proc
• mmap, munmap - map or unmap files or devices into memory
• Is it possible to create a directory and file inside /proc/sys?

@mark-plotnick suggested POSIX shared memory, which does support names.

Further reading:

• Posix shared memory vs mapped files (versus mmap, for example)
• shm_overview - overview of POSIX shared memory
• shm_open, shm_unlink - create/open or unlink POSIX shared memory objects
  (These are named objects)

  The operation of shm_open() is analogous to that of open(2). name specifies the shared memory object to be created or opened. For portable use, a shared memory object should be identified by a name of the form /somename; that is, a null-terminated string of up to NAME_MAX (i.e., 255) characters consisting of an initial slash, followed by one or more characters, none of which are slashes.

• shm_open - open a shared memory object (REALTIME) (POSIX)