Is there a way to go back through a tree to already visited node?

[ArturBraun]

I want to parse a "while" loop. My idea is to:

1. Check the while loop condition (If it’s false, jump to next node after ending of while nodes)
2. If condition is true execute statements inside while loop
3. If I meet the end node of while loop then I jump to the while loop beginning node and do step 1.

My question is as subject above. How to jump back to already visited node? Or maybe you have differents approches to parse the while loop. All ideas are welcome!