You can choose which fields to be previewed on the portal/shared view, or linked records on the form. There are 3 ways from which you can choose in the Fields setting:
Use the same fields from the expanding form
Select custom fields
Use Airtable view fields (not available on the form)
The Fields setting can be found here:
For a linked record field on a form, in the View section of that field's settings.
For a portal/shared view, in the Views section, under Default Fields. Note: This may be overriden by specific views, if they are set to use custom view settings in the View Type section of their configuration. In this case you will find this setting in the Fields section of your view's settings.
1. Expanding Form
By changing which fields are shown on the expanding form, as well as adjusting their order, you can determine how fields are displayed in a portal/shared view, or in the linked record field.
Note that linked records are 'expandable' by default if the linked field has a child form (allows expanding/editing).
2. Select Custom Fields
There is an option to override the default preview fields by setting up Custom fields. Instead of showing the fields of the child form, you'll pick a list of fields in this option. This will affect the grid, list, and gallery view.
To do this, select the fields under Default Fields in the View section (or per view, if the view uses custom view settings).
3. Use Fields from Airtable View
When using the fields from an Airtable view, the fields that are visible in that view will determine which fields will be shown on the portal/shared view.