In an Integration where possible we will try to use existing standard fields in platforms to store your synced data, however, on occasion there isn't a relevant field and a custom field is required. Below we show you how you can find & view your custom fields on an entity in HubSpot.
From your HubSpot record (Company, Contact, Deal etc) navigate to the 'Actions' menu and select > 'View all properties'
You will then be taken to the 'Manage Properties' page for the record you are viewing and be shown a search box. When integrating fields from another platform we will generally put the platform name at the start of the custom field. EG: MYOB or NetSuite, followed by the name of the field we are syncing.
If you enter the name of the platform that is being synced to HubSpot you will see all the integrated custom fields.
In the screenshot below you can see we are syncing NetSuite data into HubSpot.
The below-linked help article will show you how you can see what fields are in your Integration:
How do I see what fields / sync rules are in my integration?
For more information on customising HubSpot record views, see the below HubSpot help article: