(setq org-agenda-custom-commands
      '(("c" "My TODOs"
         ((tags-todo "mytag"
                     ((org-agenda-prefix-format " %e %l ")
                      (org-tags-match-list-sublevels t)))))))

Debugger entered--Lisp error: (wrong-type-argument buffer-or-string-p 3)
  get-text-property(0 extra-space 3)
  (concat level "" (get-text-property 0 (quote extra-space) level))
  (if (equal level "") "" (concat level "" (get-text-property 0 (quote extra-space) level)))
  (format "%s" (if (equal level "") "" (concat level "" (get-text-property 0 (quote extra-space) level))))
  (format " %s %s %s " (format "%38s" (if (equal breadcrumbs "") "" (concat breadcrumbs "" (get-text-property 0 (quote extra-space) breadcrumbs)))) (format "%6s" (if (equal effort "") "" (concat effort "" (get-text-property 0 (quote extra-space) effort)))) (format "%s" (if (equal level "") "" (concat level "" (get-text-property 0 (quote extra-space) level)))))
  eval((format " %s %s %s " (format "%38s" (if (equal breadcrumbs "") "" (concat breadcrumbs "" (get-text-property 0 (quote extra-space) breadcrumbs)))) (format "%6s" (if (equal effort "") "" (concat effort "" (get-text-property 0 (quote extra-space) effort)))) (format "%s" (if (equal level "") "" (concat level "" (get-text-property 0 (quote extra-space) level))))))

(setq org-agenda-custom-commands
      '(("c" "My TODOs"
         ((tags-todo "mytag"
                     ((org-agenda-prefix-format " %e %b ")
                      (org-tags-match-list-sublevels t)))))))

(setq org-agenda-custom-commands
      '(("c" "My TODOs"
         ((tags-todo "mytag"
                     ((org-agenda-prefix-format " %e ")
                      (org-tags-match-list-sublevels 'indented)))))))

(setq org-agenda-custom-commands
      '(("c" "My TODOs"
         ((tags-todo "mytag"
                     ((org-agenda-prefix-format " %b ")
                      (org-tags-match-list-sublevels 'indented)))))))