Below is the modified version of org-make-link-regexp
which will allow one nesting level of square brackets inside description:
(defun org-make-link-regexps ()
"Update the link regular expressions.
This should be called after the variable `org-link-types' has changed."
(setq org-link-types-re
(concat
"\\`\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):")
org-link-re-with-space
(concat
"<?\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):"
"\\([^" org-non-link-chars " ]"
"[^" org-non-link-chars "]*"
"[^" org-non-link-chars " ]\\)>?")
org-link-re-with-space2
(concat
"<?\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):"
"\\([^" org-non-link-chars " ]"
"[^\t\n\r]*"
"[^" org-non-link-chars " ]\\)>?")
org-link-re-with-space3
(concat
"<?\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):"
"\\([^" org-non-link-chars " ]"
"[^\t\n\r]*\\)")
org-angle-link-re
(concat
"<\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):"
"\\([^" org-non-link-chars " ]"
"[^" org-non-link-chars "]*"
"\\)>")
org-plain-link-re
(concat
"\\<\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):"
(org-re "\\([^ \t\n()<>]+\\(?:([[:word:]0-9_]+)\\|\\([^[:punct:] \t\n]\\|/\\)\\)\\)"))
;; "\\([^]\t\n\r<>() ]+[^]\t\n\r<>,.;() ]\\)")
org-bracket-link-regexp
;; "\\[\\[\\([^][]+\\)\\]\\(\\[\\([^][]+\\)\\]\\)?\\]"
"\\[\\[\\([^][]+\\)\\]\\(\\[\\([^[]*?\\[[^]]*?\\][^]]*?\\|[^][]+\\)\\]\\)?\\]"
org-bracket-link-analytic-regexp
(concat
"\\[\\["
"\\(\\(" (mapconcat 'regexp-quote org-link-types "\\|") "\\):\\)?"
"\\([^]]+\\)"
"\\]"
"\\(\\[" "\\([^[]*?\\[[^]]*?\\][^]]*?\\|[^]]+\\)" "\\]\\)?"
;; "\\(\\[" "\\([^]]+\\)" "\\]\\)?"
"\\]")
org-bracket-link-analytic-regexp++
(concat
"\\[\\["
"\\(\\(" (mapconcat 'regexp-quote (cons "coderef" org-link-types) "\\|") "\\):\\)?"
"\\([^]]+\\)"
"\\]"
"\\(\\[" "\\([^]]+\\)" "\\]\\)?"
"\\]")
org-any-link-re
(concat "\\(" org-bracket-link-regexp "\\)\\|\\("
org-angle-link-re "\\)\\|\\("
org-plain-link-re "\\)")))
But as noted above, this doesn't solve the problem of editing links (Org will still want to replace brackets with braces.) This also can only handle one nesting level of one bracketed group.