Today I have signed up for two group conversations and, when asked if I wanted to invite any friends, I found myself in trouble. First, I don’t know all my “friends” by their username only (sometimes I added people who are learning Italian but don’t get to know them enough to memorize their usernames). Second, I don’t know what languages each of my contacts is learning. So, I thought it may be useful to have only the contacts studying that language listed, and not all of them. I have no idea of whether it’s doable and of how much effort it would require, though.
Thanks for reading this, anyway. 
Hi Michele,
Thankfully this functionality already exists
If you go to the Friends page and use the filters on the right you can sort your friends by specific languages. Though they may not be actively studying the language, if they have had any sort of interaction with the language (i.e. creating LingQs, etc.) on LingQ then they will appear for that language.
Alex,
it seems my question was not clear enough, since you are the second person who misunderstands it. I meant to ask if it is possible to have only the students on one language appear in the window we see after booking a group conversation. As of now, when you have to select the friends you want to invite, you see all of them without being able to filter them. Yes, I could open another tab and filter them in the Friends page, but it takes more time.
I hope my question is more clear now.
Michele,
I see what you mean now. My gut reaction is to say that we probably won’t be adding this just yet, as Group Conversations are a very small percentage of the total conversations that take place through our system, but it certainly does make sense. I’ll run it by one of our programmers to see how complex something like this would be, but it will definitely go on our list of things to do.
Thanks for clearing your question up!
Thanks for considering my request, Alex, even if I do realize it’s not a priority.