Issue Summary

When using the custom PDF export feature, the exported PDF file name does not include the page title of the parent page in the page tree. This makes it difficult to identify and organise the exported PDFs, especially when multiple files are generated.

Steps to Reproduce

1. Select the custom PDF export option from the space settings
2. Navigate to the page tree that you wish to export as a PDF.
3. Select the custom PDF export option.
4. Complete the export process.
5. Observe the file name of the exported PDF.

Expected Results

The name of the exported PDF includes the title of the parent page of the exported page tree.

Actual Results

The exported PDF name contains the space key and the exported time.