Common documents for members of different projects
Add the ability to download documents that are available to all groups, regardless of projects.
For example, corporate rules, standards should be available to members of different groups. This is necessary so that in case of changing these documents, members of different groups always have access to the changed documents automatically.
Dominic Moss commented
Content Types in SharePoint address this requirement. If your source content document changes all libraries on all sites that use that content type have access to this updated document automatically. I prefer to create a document library in which my source documents reside and to then use their URLs when defining new content types.
Igor Yanshin commented
For each project now I can make a SharePoint site with documents, but I can't add one document for each groups. Not many documents - one for each group, but just one document for all groups