I have a sharepoint list - a master projects list used in libraries and lists with lookup. Can i host this list on my top level sharepoint site and share it with my 5 other sub-sites? Want to avoid maintaining it in 5 different places.
Yes. You can add a nav link to it in a hub site assuming you have sub sites or some other way. But in the list with the data just go to list settings and you can go to list permissions and put in custom permissions you will need to stop inheritance on the list to do so. Once you do anyone you add or anyone in a security you you assigned can access only that list.