why I am getting error on Edge Selection

Hello, I have a hexagonal lattice feature which intersects a flat surface at 90` I can add the vertical rounds to the lattice itself via the feature, but is there a quicker way to add rounds to the edge that intersects the lattice and flat surface? rather than selecting each of the bottom edge of each of the hexagons? There is approx 150 Cells in the lattice and its quite tiresome to add them all in. Other CAD platforms have intersection selection control, but i cant seem to find anything in creo, even using closed/partial loop or selecting edges by filter?

Any help will be appreciated.