You can organize pages in a hierarchy, with child and/or parent pages for closely related content. When you navigate to a page in collaborate.green and choose the Create button in the header, the page you're creating will by default be a child of the page you're viewing. Have as many child pages and levels in the hierarchy as you need to, and move pages if you want to change their location.
Each time you create a page, you're creating it in a space. Spaces are containers used to contain pages with related content, so you can set them up for each team in your organization, for projects, a combination of both, or for any reason you want to group pages together. See Spaces, pages and blogs for more information.