I hate to be a pessimist but it's gonna be damn near impossible. It's like knowing a band দ্বারা a few promo pics as opposed to songs and band name (trust me I speak from experience).
I'd say your best bet is to try googling a মতামত they left? If আপনি remember any of them. It would probably have to be word for word though. অথবা if they were on an unpopular club আপনি can go there and try to find them. Other than that I don't really know of a way.
আপনি can't A person's ign is their calling card if আপনি can't figure that out. আপনি can't figure out which ব্যবহারকারী নাম your friend has. It's like going into a neighborhood and forgetting what address your friend has. No identification no pinpoint shot to finding ব্যক্ত friend..
