You can change the record title for linked record fields on the form, or records in the portal to something different by going to:
For a linked record field on the form:
Select the linked record field
Go to View
Set Record title to Select another field
Set Custom field for record title value accordingly
For a table/view in a portal or shared view:
Tables
Views
Under Default Fields, set Record title to Select another field
Set Custom field for record title value accordingly
If your views are set to override default view settings (under the View Type section of your view's settings), you'll need to change this setting on a per-view basis (under Record Title), instead of just in the default fields settings.
💡 Note: Attachment fields and linked records field types cannot be selected for this feature.
Troubleshooting:
If you see the error message 'Could not find a primary field for the table,' check that all linked-record fields, where the 'Record title' is set to 'Select another field,' have a custom field selected.