Two-faced one shows agreement to a German sunrise (5)
I believe the answer is:
janus
'two-faced one' is the definition.
(I've seen this in another clue)
'agreement to a german sunrise' is the wordplay.
'agreement to a german' becomes 'ja' ('yes' in German).
'sunrise' becomes 'nus' (I can't explain this - if you can you should give a lot more credence to this answer).
'ja'+'nus'='JANUS'
'shows' acts as a link.
Can you help me to learn more?
(Other definitions for janus that I've seen before include "Two-faced person" , "Two-faced deity" , "Roman god of doors and beginnings" , "Two-faced god of gates and doors - Guardian cryptic crossword setter" , "Roman god of doors, usually two-faced - a month is named for him" .)