@abm - Thanks for the response. Here is a summary of workflow I would like to create to see if it works out.
I am using MS Forms as the user interface for users to submit information. I will create branch question in MS Forms to identify if the request is for a new Purchase order information setup or Invoice for approval and tracking purposes.
If it is for a new Purchase order setup. I will direct the form submission to create a new record in a list called purchase orders. I need to make sure before the record is entered, no prior entries exist for the purchase order based on a field File number.
If it is a for invoice entry to track against an existing purchase order. I will direct the form submission to create a new record in the Invoice tracker list and create a workflow for persons responsible for approving this invoice. If the invoice is for File "Apple" designated Approver is John Smith. I want to copy this record to list called Approvals for John Smith.
If the invoice already exists, I need to create an alert for duplicate or copy the record to an exception list for review.
@abm to answer your questions
Is this duplication file check is against a single list record? - Check if File number or Invoice number exists in a single list (check all records in the list).
The means first validate to check the existing invoice or not? Yes first validate to see if it exists.
If record exists then search the file against the related attachment(s) stored against that record. You are not looking for all the attachments under the lists? Isn't? Could you please explain? - I am not sure. I want to make possible to add attachments (contracts for purchase orders, Invoice (pdf) for Invoice tracking.