Oracle Analytics - Creating an analyses to display all rows with same values in certain fields

kt838

Hi all, first time poster here so hope I'm in the right place! I'm using OACS to develop a report/analysis to list any duplicated invoices in the system. The initial idea is to potentially use a Group By clause to group rows by the following fields: Invoice Number, Invoice Date, Invoice Amount and do a count of rows where if the count all rows are to be displayed. Screenshot of the current design as follows:

Does anyone have any idea how do I go about doing this in OACS? I'm not familiar with the more advanced features so will appreciate any advice!