Term for reverse lookup of concepts
I'm not sure that any such specialized term exists, or at least I have never heard of such.  The process, however, is quite familiar to me.  I find it most interesting when I discover that several different subjects have all approached the same topic from different directions, each typically having invented its own largely unrelated terminology.

As for what to call it? I would typically refer to it simply as searching for related work and then connecting my work to the prior results.  It might be a fun target for a neologism, though!