I believe the search you are currently doing is looking for clips with the name Gabrielle in them vs. clips that have been keyworded with Gabrielle (i.e. you could search for 1904 here to bring up the MVI_1904 clip).
Using the filter window (click on the magnifying glass in the search field) you could create a search that would allow you to make a new collection of clips tagged with either or both the Gabrielle and Hanoi keywords (click on the “+” and check the Gabrielle and Hanoi checkboxes, and set keywords to “include any” or “include all”).
I hope this is what you were looking for?