You can manage and configure the Parent-Child interlink support for the “Add” Form Type. You will get the “Parent-Child Link” option under the Advanced Configuration accordion.
You need to select the Add Form Type and enable the “Parent-Child Link” option. You need to select another Entity as “Child Entity” which should be related to the parent entity.
Once the Parent-Child Link is enabled, you need to select the ‘Entity’ and its ‘Relationship type’ from the drop-down option. You will get the Field selection as per the Relationship Type. You can drag & drop required fields to the Form builder.