Extensive view of old queen in a hat (8)
I believe the answer is:
panorama
'extensive view' is the definition.
(I've seen this in another clue)
'old queen in a hat' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'queen' becomes 'r' (abbreviation for regina, e.g. in ER ).
'in' means one lot of letters goes inside another.
'a hat' becomes 'panama' (panama is a kind of hat).
'o'+'r'='or'
'or' placed within 'panama' is 'PANORAMA'.
'of' is the link.
(Other definitions for panorama that I've seen before include "Am on a par (anag)" , "Wide-angle shot" , "Unbroken view of surrounding area" , "Wide view of surrounding area" , "Wide view of region" .)