You should probably go with H chair toss for Beo. Filia's main need is an assist to augment neutral.
I don't really know what Beo needs, but you can't go wrong with H Updo. If you feel like you need lockdown and some space creation, then go with go with H hairball. Filia also has c.mk, but I would not recommend that assist unless you have another character that provides a spectacular assist already.
I don't think that Filia and Beo have decent damage assists that are noteworthy in combos(besides maybe H hairball, and I doubt that Beo can really get the most out of it.)