Group of stars initially observed networking around Brazilian city (5)
I believe the answer is:
orion
'group of stars' is the definition.
(I've seen this before)
'initially observed networking around brazilian city' is the wordplay.
'initially' says to take the initial letters.
'around' means one lot of letters goes inside another.
'brazilian city' becomes 'rio' (I've seen this before).
The first letters of 'observed networking' is 'on'.
'on' placed around 'rio' is 'ORION'.
(Other definitions for orion that I've seen before include "Hunter slain by Artemis" , "Major constellation" , "He hunted" , "Heavenly figure" , "Mythical Greek hunter turned into constellation" .)