The portfolio should be able to be filtered by labels.
The ranking order resulting from the overall list should be retained for the filtered lines.

 Example for filtering:

 #     Title                                    Labels

1     Epic A                                  x,y,z
2     Epic B                                   y
3     Epic C                                   x, z
4     Epic D                                   z
5     Epic E                                    x

 Filtering to “x”: 

#     Title                                    Labels

1     Epic A                                  x,y,z
3     Epic C                                  x, z
5     Epic E                                  x