You can sync your SharePoint Online files to a folder on your computer where you can work directly in File Explorer and access the files even when you're offline. Whenever you're online, any changes that you or others make will sync automatically.
Once you open MS Teams Application, you will get the teams that you have added.
Select the Channel where the documents have been added and you want to sync in local machine.
Select Channel> click on ‘Files’ Tab, you will be getting the document folder, this process is applicable for all the Channels.
Select the File and select “Open in SharePoint” option available in the teams, see the below image for more details.
It will redirect us to the browser, now click on sync button available in the Site, Click Documents or navigate to the subfolder you want to sync.
Click the Sync button. (You only need to do this once in a computer to set up syncing on that computer. After you set up syncing, the files sync automatically.)
If your browser requests permission to use "Microsoft OneDrive," confirm.
Choose the folders that you want to sync, and then click Start sync, for example, I am selecting I subfolder from the files, we can clear all checkboxes from the folder and navigate to the particular folder which we want to sync.
The files will sync to a folder on your PC that has the name of your organization (for example, %userprofile%\cvbn). This folder is automatically added to the left pane in File Explorer. You can’t select to sync to a different location.
The moment it’s getting synchronized, we can track or monitor as well by clicking on the OneDrive icon from taskbar, which will show the status of file synchronization.
Once it's done we can see that the folder structure will copy from parent and will sync only the selected folder which we have added for sync, also we can notice that OneDrive Icon in the taskbar will be clear once it’s synchronization is completed.