To do so, you need to get just a bit creative. Essentially, you can create multiple success/failure paths from one step to multiple steps.
Doing so, will allow the user to choose a specific step during task sign off.
For example, in the following workflow, when the post/page is on the “1st Level Review” step, the user can either choose to go to “2nd Level Review” OR skip this step and directly go to the “Publish” step.