To bring a product on top, you need to create first your Rule and connect it to the right widget (see topic 1 for support on this)
Bringing a product on top is defined by the right part of the edition or the Rule: the Effect. Indicate what product you want to put on top (for example: field: "id" and values with the id of the product, then select the effect "rank" and put the ranking position to 1. If your product was already in the result list (but not on top) that's enough, but if your product was not there, you must also select the check box "force include" to include it in the results. Otherwise, it will be pushed on top only if it was already part of the results and not otherwise.
...