I've been trying to validate the user entered information(in the UI) with the existing data page values....how to use date page values in validate rule so that check whether the entered value is already present or not??
***Edited by Moderator: Lochan to update platform capability tags***
As mentioned in the link by @ chouk1, you can use something like @(Pega-RULES:Utilities).IsInPageList(.Country,pyCountry,D_GetLinkedCountries[UserId:OperatorId.pyUserIdentifier,Application:.Application].pxResults) in validate rule.
Or as below, where EmpID string value is being looked for, .EmployeeID is being looked at, within D_JobsByDay data page. Use UI property value for your case instead of EmpID string.