I would like to place the projects 'Samen Meten aan Luchtkwaliteit' and 'Samen Geluid Meten' as headers under the category Environment of a bunch of other projects in a sub-bullet point style. They are both not exactly citizen science projects themselves, but the RIVM supports a lot of citizen science projects with these projects and stores their data on their data portal. Is it possible to relate the projects to each other in this way and how would I do that?