For every document or folder, you can manage who can view or download it. Alternatively, you can copy the link to it and share with others.
Go to Documents.
Locate the folder or the document you want to share.
On the three dots options menu, select either:
View details.
Manage access.
Copy link - simply copies the link to your clipboard to share with your colleagues who have access. If they do not have access, you will need to manage this with Manage access.
With each of these, you can share your document.
You can also use right click on your item to access a context menu
View details and Managing access
Either, once you have opened your document's details, or in the context menu, select Manage access.
Then select move the toggle to allow or restrict view, download or manage access for each group or user.
Select Save.