Users with a Manager Licence and Modify rights who have a Portfolio currently selected will be able to produce a custom Portfolio report from here.

Simply select the items you want including the data range and view required for Tasks, Risks, Issues and Properties, then press the Portfolio report button in the Create Report pane to the right.

Once the report has been produced the right hand side will update with viewing and publishing options as shown here:

Simply click on the Open/download report links to look at the report in those formats (opening in a new window) or you can publish the report back into the project using the Publish options at the bottom of the pane.