The FE7if wiki lists all the songs in the soundroom as well as the game or media it originates from, but it’s all in Japanese. You can probably find the song just by google translating everything though.
There are some YouTube channels out there that post the FE7if OST but none of them are complete as far as I’m aware. If there’s a specific song you’re looking for, I can help you since I’ve been working on the music for a hack based on FE7if and have been listening to a lot of its soundtrack lately.