Variables are a way to re-use content across your Account, a Brand or event a specific campaign. It's designed to save your fingers by having some common phrases, call-to-actions, products or other content saved.
When on the Variables page for a Campaign, it will provide a simple view of the Variables available for that campaign - either tagged Post Maker, Account or specific Brand or Campaign
So you have used a variable in your post and want to use the same generation within a post. Here is how you do it: 1) Write up the post using the variables you want to use 2) When it comes to where you want to reuse the spun variable type "!!x" where X is the number of the variable position (if it's the first variable used in the post then x would be 1)