This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 徸 is uncertain. It visually combines 彳 (movement) and 童 (child), but the original meaning and component relationship are unclear.
With no clear meaning, picture a child (童) walking (彳) aimlessly, representing an uncertain or lost idea.
For ショウ, imagine a child (童) walking (彳) to a show (ショウ) but getting lost because the kanji's meaning is unclear.