Скачать или смотреть Create Lookup Filters in Trailhead

Create a Lookup Relationship
Create a new Backup Agent field that looks up to the User object, editable by Support Users only.

From Setup, click Object Manager and select Case.
Select Fields & Relationships and click New.
Select Lookup Relationship as the Data Type, then click Next.
Select User from the Related To picklist, then click Next.
Rename the Field Label to Backup Agent.
Rename the Field Name to Backup_Agent.
For Description, enter: Used to identify the assigned support rep when case owner is away — for support use only.
For Help Text, enter: Who is the assigned support rep when case owner is away?
In the Lookup Filter section, click Show Filter Settings.
Click the Find icon Lookup iconto select the Field, and fill in the filter details
Field Operator Value/Field
User: Profile: Name
equals Value / Support User
Leave everything else as is and click Next.
In the Read-Only column header, select the checkbox.
In the Read-Only column, deselect the Support User checkbox.
Click Next.
Deselect the checkbox in front of the Close Case Layout.
Click Save.
Add a filter to the case Contact Name field so that users can only select contacts related to the account selected in the case Account Name field.

While still viewing the Case object, select Fields & Relationships.
Select Contact Name, then click Edit.
In the Lookup Filter section, click Show Filter Settings.
Click the Find icon Lookup iconto select the Field, and fill in the filter details.Lookup Filter showing Field, Operator, and Value/Field filled in for the new Lookup Relationship on the Case object.
Field
Operator
Value/Field
Contact Name: Account ID
equals
Field / Case: Account ID
Ensure Required is selected next to Filter Type.
Leave everything else as is and click Save.