How can I migrate and merge a set of jira projects into a single project on a new server?

We have a set of Jira projects on a server, which we have to transfer to a new server. At the same time, we want to merge these projects into one project.

How can this be done by preserving workflows, columns, permissions, filters, components, etc.?

I see how to migrate an entire server, one for one, but I do not see any way to merge and migrate selected project instances. In addition, the target server already hosts many other projects, which we do not want to lose sight of.