Suppose a matrix $A$ where each row represents a transaction, and each column represents an SKU (product). Each cell is either 1 or 0, meaning whether a product was purchased in a transaction. Product pair (two-product) co-occurrence matrix is essentially $A^TA$.
However, I'm stuck with three (and maybe more) products co-occurrence. By analogy I would expect to get a 3-D "matrix", but I cannot think of any linear algebra operations that produce 3-D matrices out of 2-D.
(By counter example, it is easy to show that three-product co-occurrence is not chaining two product pairs.)