HR/Manager able to see employees' questionnaire in Journeys

Hello,

We're in the process of setting up a Journey which must satisfy the following two requirements:

1. It has to be available under the "Explore" tab, so that employees can search and self - assign to them;
2. At the very beginning, employees are asked to fill in a questionnaire. Questionnaire's answers must be visible to the next actor (HR) in order for him/her to fill in another questionnaire, which in turn must be visible to the following actor (employee line manager)..

Requirement 2 is feasible when the Journey is assigned centrally, using "Allocate Checklist" task. We aren't able to reach the same behavior when employees self assign the Journey in the "Explore" tab, as HR/Manager don't see the Journey in "Assigned Journey" but only a single task in "My Tasks". Any idea or workaround in order to fulfill this?