Ideally, this is something to research before you buy the domain.
Identifying potential buyers depends largely on what type of name it is. If it's an exact match product or service name, your best targets are typically companies who have a major focus on that product or service. If it's one of dozens or hundreds of their offerings, then it's much less likely that they'll be interested in the name.
If the name is geo-specific, generally your potentially buyers would be anyone in that geographic area offering the service/product specified by your name.
If the name is a brandable, it's a little harder to find targeted buyers, as you run into the risk of a legal dispute by approaching companies that are using the same (or similar) name already. I personally never do outbound marketing with brand names, but if you were going to, then you could focus on targeting full-service marketing companies or large corporations that like to "bank" domains for potential future use with products or campaigns.
It would be much easier to provide you with guidance if you could share the name.