To make it simple, let's say that I play a game that opens with 1. e4 d5 2. d4.
I use Scid-vs-PC, and in this position, it just shows a bunch of games. Od course, if black plays now 2 ... e6, we transpose into the French defense, and suddenly thousands of games exist.
I'm looking for a software that after 1. e4 d5 2. d4 will show you the games that transpose to the French Defense.
I'm not sure if I'm explaining myself properly. So, just in case, this site has this feature that I'm attaching a picture of to show both cases in chesstempo