The most common and most likely answer to this crossword clue is the 8 letter word CHOROIDS
I've seen this crossword clue in Financial Times
C
H
O
R
O
I
D
S
Buddy explains!
The straight part
We know that "sections of the Observer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sections of the observer = choroids.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CHOROIDS mean?
CHOROIDS noun- The pigmented vascular layer of the eyeball between the retina and the sclera.