If you don't like loops, you can put steps in a sequence. So you can do multilevel approval by doing them one after another:
+----------+
| Approve |
| Level 1 |
+----+-----+
|
+----+-----+
| Approve |
| Level 2 |
+----+-----+
|
+----+-----+
| Approve |
| Level 3 |
+----------+
In between you would obviously add some conditions to check whether to proceed to the next approval or end.
Regards,
Mike