The filters that ship with BorisFX, Boris Graffiti and also Boris RED are for use only within the application that they are installed with. You cannot drag the filters from Boris FX and use them in After Effects. And this actually should be expected. For instance, you cannot drag the AE native filters from AE and use them in any other application. This is because like the effects that ship with FX/Graffiti/RED they are application specific.
You can purchase the BCC filters and use them inside of AE - this works quite well. The BCC product that you can download and install into AE is a different product than the filters that ship with FX/Graffiti/RED. The filters that ship with FX/Graffiti/RED have been optimized for these host applications before they were added to the product.