import re

pattern = r"([^\s()]+\([^()]*\))|(\([^()]*\)[^\s()]+)|[()]"
a = 'abc (xyz pqr) qwe ew (kjlk asd) ue(aad) kljl'

y = [x.strip() for x in re.split(pattern, a) if x and x.strip()]
print(y)