Climb up again to adjust compass (7)
I believe the answer is:
rescale
This clue is a double definition.
'climb up again' is the first definition.
('scale' is an answer for 'climb up' so perhaps 'rescale' is OK for 'climb up again')
'adjust compass' is the second definition.
'to' acts as a link.
I've seen this clue in The Independent.
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