Org Weekly Agenda filter tags with logical OR

Question

Background information to motivate my question:

With the agenda open, I can press "\" then "+" to show only results containing a certain tag, say A. I can then press "\" and "+" again to show results with both A and another tag, say B. These combinations are boolean expressions of the tags AND'ed together: A AND B for the former and A AND NOT B for the latter.

My question:

I would like to filter my agenda in the same way but with the union of tags A and B, so that any entries with either tag A OR tag B are shown (A OR B). How can I do this?

org-agenda-custom-commands can define tag searches using the full boolean expression syntax described in the manual (as described in the answer to this question), so that defining a custom command like
(setq org-agenda-custom-commands '(("z" "test" tags "A|B")))
but these searches do not produce a weekly agenda. For example, they are not sectioned by date, they do not only show scheduled and deadline items, and they do not show upcoming deadlines.

How can I filter the weekly agenda using a query for tag A OR B?

Answer 1

You have to use a skip-function. For details see this page. Adjusted to your needs the function there would be:

(defun my-skip-tags ()
  (let ((subtree-end (save-excursion (org-end-of-subtree t))))
    (if (not (or (re-search-forward ":A:" subtree-end t)
                 (re-search-forward ":B:" subtree-end t)))
        nil          ; tag found, do not skip
      subtree-end))) ; tag not found, continue after end of subtree

This solution does not work, though, if you want to filter by inherited tags. For this case I use the following function:

(defun my-skip-inherited-tags ()
  (let (beg end m)
    (org-back-to-heading t)
    (setq beg (point)
          end (progn (outline-next-heading) (1- (point))))
    (goto-char beg)
    (setq alltags (prin1-to-string (org-get-tags-at)))
    (goto-char beg)
    (if (not (or (string-match "A" alltags)
                 (string-match "B" alltags)))
        end)))