The requirement is to display the lines related to the currently logged-in customer in the customer center and eliminate the lines associated with other customers from the custom record.
Use Formula Numeric in the saved search Criteria “decode({custrecord_vr_thirdparty_ship_cust.id},{user.id},1,0)”

decode function:
The decode function is commonly used in NetSuite to provide conditional logic. It works like a case statement.
In this context, it's used to compare the value of {custrecord_vr_thirdparty_ship_cust.id} with {user.id}.
{custrecord_vr_thirdparty_ship_cust.id}:
This represents the value of the field with the internal ID custrecord_vr_thirdparty_ship_cust.id. It's a specific field in a NetSuite custom record.
{user.id}:
This represents the ID of the current user executing the saved search. It is used for comparison within the decode function. The user logged in the customer center.
1 and 0:
These are the values returned based on the comparison result. If the value of {custrecord_vr_thirdparty_ship_cust.id} is equal to {user.id}, the formula returns 1; otherwise, it returns 0.
In summary, this formula is likely designed to check whether the ID of the custrecord_vr_thirdparty_ship_cust field matches the ID of the current user ({user.id}). If there's a match, it returns 1; otherwise, it returns 0. This can be useful for creating a numeric indicator based on a specific condition in the context of a NetSuite saved search.