I am using the Trace Geometric Network Tool (10.5.1) in conjunction with the HEM tool from USGS in order to import an existing point layer as my "flags". This works really well to save time in setting the flags by hand (I am interested in finding upstream flowlines of a polygon layer -- so I intersected the polygon layer with the flowlines to create a point layer where each polygon intersected with streams).
The problem is, when I run the upstream analysis, I do have resulting upstream flowlines selected, but there is no field that references the initial flag layer. I need this in order to distinguish what the flow-line is upstream of, as I have several polygon features in my layer. It would be very cumbersome to run the upstream analysis for each polygon separately. Is there a way to save an attribute of the initial flag layer to join in final results table?