Hi, @u01brb2. If it's possible for your org, there are native features from the Salesforce connector which would allow you to import those opportunities without a .csv.
The most straightforward way to accomplish this is by choosing the import option to import directly from Salesforce, choosing the Opportunities import. The tradeoff here is that it will import all opportunities, and can be a little overreaching for some orgs.
Alternately, if you're associating contacts with opportunities in Salesforce as opportunity contact roles, you can just turn on opportunity sync, then resync all contacts in HubSpot syncing to Salesforce (API calls permitting). By the time the sync completes, all deals your HubSpot contacts are associated with in Salesforce would appear in HubSpot.
If you haven't installed the connector, or neither of the above use cases apply because you have a more selective set of opportunities to import, use the steps @Phil_Vallender outlined.
Brad Mampe, Salesforce Analyst, Fidelity I'm probably wrong. I may not be right about that.