Need to add Descriptive Flexfield segments in Contract Invoice

Summary:

 Need to add Descriptive Flexfield segments in Contract Invoice, Expenditure Items section

Content (please ensure you mask any confidential information):

We have implemented Project Billing based on Percentage of Cost and we are storing some information as part of our cost capture, user defined attribute. When Project Invoice is generated, we want user defined attribute to be displayed in the expenditure items section of the Invoice Lines, for the user to take appropriate action. We tried to do this via page composer but the DFF was not available in the table. Also Project Costing DFFs are not available for Invoice Formats as well.