Second XI from Bundesliga showing personality (4)
I believe the answer is:
self
'personality' is the definition.
(I've seen this in another clue)
'second xi from bundesliga' is the wordplay.
'second' becomes 's' (common abbreviation).
'xi from bundesliga' becomes 'elf' (I can't explain this - if you can you should give a lot more credence to this answer).
's'+'elf'='SELF'
'showing' is the link.
Can you help me to learn more?
(Other definitions for self that I've seen before include "Will the author" , "A person's awareness of their own identity" , "One's individuality" , "Will perhaps" , "one's identity" .)