Forcefully introduce your friends to each other and/or find a group and join it. Ik it sounds simple but that’s probably the easiest solution. Just start telling your friends about each other and then be like hey!! Wanna go to the park with us! Wanna get drinks! Wanna do puzzles or go to the beach!!
I feel like college isn’t really the environment where that’s possible easily anymore. I also had a few big friend groups that I forced to hang out with each other at times in high school, and now I go to college w a few on my friends? But meshing friend groups isn’t as easy where and you tend to make friends in individuals and it’s a coincidence if a few of your individual friends know and like each other and maybe wanna hang out altogether. It’s j a totally different environment tbh