Multilevel bullet/ordered lists are currently not supported in eZ ODF. See doc/ezodf_extension_documentation.pdf within the ezodf extension, page 8:
"3.3. Supported formatting
When importing text into XML text fields, the following formatting styles are supported:
(...)
Numbered and bulleted lists (one level)"

When importing documents with such lists, the import appears to succeed, apart from PHP warnings like:
Warning: DOMDocument::loadXML() [domdocument.loadxml]: Opening and ending tag mismatch
Warning: DOMDocument::loadXML() [domdocument.loadxml]: Extra content at the end of the document in Entity

The object is created in eZ Publish, however it contains invalid XML. Viewing or editing it shows no content, and again the same PHP warnings are displayed.

The import should refuse to create the object in this case, and show an error message about why it was rejected.