While there is not an automated process to migrate your data, if this is a project you are interested in I would suggest either reaching out to the Jive Developers space here in the Jive Community where you can collaborate with other developers on potential migration processes (specifically the Jive REST Rest API v3.10 might meet your needs).
Additionally, if you would like assistance developing a migration tool our Professional Service's team can work with you to determine the scope of the project and work with you to migrate your content. If you are interested in this option please submit a case in your customer group here in the Jive Community and the next available support engineer can assist in setting this up.
Have you designed / architected where things in Jive will be heading when going into Confluence? Or, is this something you are also wanting assistance with as well?
Just a note, have you seen: Demo of Immersive for Atlassian Confluence, in Jive 6