Today, ChatGPT’s Export data is an account-level export: the ZIP includes your full chat history plus other relevant account data (e.g., conversations.json and related assets/metadata), not a per-Project export.
Exporting only one Project’s data would be a useful improvement; at the moment, the closest workaround is to export everything and then filter the conversations.json content down to the chats from that Project which is extremely time consuming and cumbersome.
Thanks,