import re

regex = r"\(([^()/]+(?:/[^()/]+)*)\)"

test_str = "stuff (word1/Word2/w0rd3) stuff, stuff (word4/word5) stuff stuff (word6) stuff (word7/word8/word9) stuff stuff, (w0rd10/word11) stuff stuff (word12) stuff (Word13/w0rd14/word15) stuff-stuff stuff (word16/word17)."
 
res = list(map(lambda x: x.split('/'), re.findall(regex, test_str)))
print(res)