To link recipes, open on the recipe you want link to, then click edit.  At the bottom of the recipe where it says Linked Recipe, press 'add', a box will open, start typing the name of the recipe you want to link to the recipe your viewing, it will autofill with matching recipe names, select the one you want then click 'save'.  Then click the larger 'save' button at the top or bottom of the recipe to close out of edit mode.