I had a question from one of my users asking about the links or groups in the Navigation pane. This user has 3 links on the left, but in Teams or Yammer has more. What governs or how do we add/remove this links?
Sites that you follow appear on the OneDrive tab, followed by frequented sites. So if you go to Team there in Teams, then Files > Open in SharePoint, top right corner follow the site, it should then show on the OneDrive page.