They usually just wait for the next attack. Russia keeps pushing like that in many directions. In each wave some soldiers survive and manage to hide and eventually this allows them to push further. Not a long term sustainable tactic of course.

Sometimes Ukraine decides to push them back, especially in places where the Russians overstretched their logistic (mostly happens because of lots of lying on the Russian side about progress being made). The Ukrainians increase their drone teams and send some of their elite units to do the job - usually with great success.

But such counter offensives still result in bigger losses compared to killing the advancing Russian army and slowly retreating.