Controlling the creation of records in the parent table when expanding a table.

[bonsai]

A child table with the same structure as the parent table is required.

Furthermore, we want to prevent records from being linked to the parent table based on the field values ​​of records created in the child table.

Is this feasible to implement?

I considered setting a filter on the parent table to prevent it from appearing in the list, but first I'd like to know if it's possible to prevent it from being linked.

[Tanushree Maiti]

In ServiceNow, while child tables creates from parent table , it inherits all fields, forms, and behaviors of parent table in a child table .
However, you can prevent child records from appearing in parent list views or being accessed there by
using ACLs (Access Control Lists) to restrict visibility to the child table only
OR
Before insert / Before update BR
With Condition: check if the operation originates from the child table OR based on field values

Refer :Avoid issues when modifying shared fields in extended tables

Prevent child records from displaying on parent table