How to use Segment in a DFF defaulting?

Summary:

A customer has a requirement where one employee can request for DoR for another fellow employee, with approval going to the other employee's manager. There are two DFFs created based on table value set. First DFF will show the list of active employees in system, and this employee number is passed as a segment parameter to restrict the second DFF which will show the current manager of employee chosen in earlier DFF. However we need the second DFF to be a text box automatically populated after choosing the employee in the first DFF. Can this be achieved?

Content (please ensure you mask any confidential information):