*Note: Links between Articles and Silos can be created automatically by ThemeMatic when in 'View Blueprint' mode - see View Blueprint
1) Click the 'Article/Silo Link' tab:

2) Click on either the 'Article to Article Link' or 'Article to Silo Link' drop-down field and pick an Article or Silo to link to:

3) Select an Article or Silo to link to for the current Article: