Which files would I edit if I wanted to do something like this? I already know I need to database edited, just trying to figure out the code structure for something like this.

Section 1, Section 2

Person can post photo to their profile

Person can post photo in section 1, but only users in section 1 can see that photo

Person can create a group in section 2 and only section 2 people can see and access that group

All features would be broken down into sections. I know it'd probably be best to be a custom script and not necessarily a premade, but do you guys think Oxwall would be the best to handle something like this as a jumping off point?