no lack on Facebook .... I need some one from La Romana they know each other is not so big place.
It's not a campo, so no not everyone knows each other. There are some Dominicans on this forum, but mostly they are American/Canadian/British expats. So if you are looking for a Dominican without giving a name or details, might be a real stretch.
Now if the person you are looking for is known for something like having a business, works at a store, etc. then it's more likely they'll be easier to find. Or if they are a motoconchista what intersection do they hang out at, if they work at a hotel which one.
Details, if you are willing to share, might help.