Hello,
You've got here all of the side door drawings with part numbers:
FIAT NUOVO DOBLO 2009 (2009-....)
eper.fiatforum.com
As there's no information in the post which Doblo do you own, I've chosen the newest, the New Doblo (2009+). There'a a search with a VIN number available. Then go to the same section and choose which plastic clip do you need. And the best would be to ask directly the dealership.