diff --git a/org-ql-completing-read.el b/org-ql-completing-read.el
index 93dbf00..9bd4ff4 100644
--- a/org-ql-completing-read.el
+++ b/org-ql-completing-read.el
@@ -81,6 +81,12 @@ For an experience like `org-rifle', use a newline."
                  (const :tag "New line (shown under heading)" "\n")
                  string))
 
+(defcustom org-ql-completing-read-group-name-function #'buffer-name
+  "Function used to generate group name in `org-ql-completing-read'.
+Function is called when need to make group name from the buffer object."
+  :type '(choice (function-item :tag "Use buffer-name as group-name" buffer-name)
+                 (function :tag "Custom function")))
+
 (defface org-ql-completing-read-snippet '((t (:inherit font-lock-comment-face)))
   "Snippets.")
 
@@ -222,7 +228,9 @@ single predicate)."
                     (or (funcall snippet (get-text-property 0 'org-marker candidate)) "")))
                 (group (candidate transform)
                   (pcase transform
-                    (`nil (buffer-name (marker-buffer (get-text-property 0 'org-marker candidate))))
+                    (`nil (let ((candidate-buffer (marker-buffer (get-text-property 0 'org-marker candidate))))
+                            (or (funcall org-ql-completing-read-group-name-function candidate-buffer)
+                                (buffer-name candidate-buffer))))
                     (_ candidate)))
                 (try (string _collection _pred point &optional _metadata)
                   ;; (debug-message "TRY: STRING:%S" string)