If this gets posted twice, I'm sorry, mangago is being a lil bitch right now.
Anyway, these are all yuri:
https://www.mangago.me/read-manga/goukaku_no_tame_no_yasashii_sankaku_kankei_nyuumon/
https://www.mangago.me/read-manga/there_s_weird_voices_coming_from_the_room_next_door/
https://www.mangago.me/read-manga/luminous_blue/
https://www.mangago.me/read-manga/watashi_no_shumi_tte_hen_desu_ka/
https://www.mangago.me/read-manga/beast_knights/ (OK I'mma be honest, I don't remember if this one has them all like each other equally or if it's a 2 people love one person who loves them both type of relationship, sorry)
https://www.mangago.me/read-manga/tachi_to_neko_docchi_ga_ii_no/
It’s a yaoi and a manga
https://www.mangago.me/home/mangalist/2688301/
there is one with twins but I put a content warning so you can just avoid it. I agree with @lemon that Canis: The Speaker is the absolute best though (≧∀≦)

Can y’all recommend me throuples where they all like each other and 2 aren’t siblings :D
Yaoi and yuri preferred but I read whatever