Friendly to all in extremes of poverty (5)
I believe the answer is:
pally
'friendly' is the definition.
(pally means friendly)
'all in extremes of poverty' is the wordplay.
'in' is an insertion indicator.
'extremes of' says to hollow out the word (remove centre letters) (only the letters at the extremes of the word).
'poverty' with its middle taken out is 'py'.
'all' going within 'py' is 'PALLY'.
'to' acts as a link.
(Other definitions for pally that I've seen before include "Intimate" , "Close, friendly" , "Thick" , "Very familiar" , "China may be so" .)