How to replicate the logic equivalent to while loop in Snaplogic pipelines

This pipeline shows how we do what you are looking for.

The XML Generator contains the following in the edit window:

With that data we map it in the mapper as follows, the output of the XML Generator is a string called xml.
We map that to the content field and also add the content-type for the Document to Binary Snap. This enables us to put the information in a native XML form, with the necessary metadata.:

Then we need to ensure no encoding takes place on the Doucment to Binary Snap, which converts the document input to a binary stream, like the output of a file reader:

After that, the XML parser can read the input stream as an XML binary document.
The output of the XML parser reads the data as follows:

Which we then need to split using the JSON splitter to process as individual documents:

And the final output of the splitter:

Let us know if this helps.