Sign put up in bistro, elevated (3)
I believe the answer is:
leo
'sign' is the definition.
(star sign)
'up in bistro elevated' is the wordplay.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'in' indicates a hidden word.
'oel' is hidden within 'bistro elevated'.
'oel' in reverse letter order is 'LEO'.
'put' is the link.
(Other definitions for leo that I've seen before include "Cancer, ___, Virgo" , "Pope" , "Name taken by 13 popes, the last dying in 1903 aged 93" , "Fifth sign of the zodiac" , "5th sign of the zodiac" .)