Because Imagine Math is a supplemental program designed to deliver a differentiated course of lessons based on students' successes and failures, it can be daunting to attempt to assign an individual lesson for a review or reteach purpose. Additionally, you will want to avoid the pitfall of a 'drill and kill' approach where students repeatedly work through the same lesson, but never manage to successfully pass it.
We recommend that you consider creating a custom pathway that is aligned to your class course map or scope/sequence; but understand that students will advance through it at a pace much different from that which you teach in your class. It may even be that you assign a very short pathway containing a small amount of lessons (perhaps only 4 or 5) related to your current classroom topic and use it as a review or to reteach in addition to the student's default pathway assigned when they first started Imagine Math.
Finally, if you notice that a small group of students has failed the same lesson after several attempts, you should offer an alternative intervention to ensure the student has mastered the concept before re-assigning the same lesson. This can be through small-group instruction using Imagine Math's Lesson Explorer tool, or even through other intervention methods that you most likely already employ in your class.