When we create Missions we have the ability to determine who within the room receives them through their "Membership".
Through selecting the "People" tab on the left side bar we are able to view who is participating within the room as well as invite and remove members.
When selecting the "People" tab you will notice a list of everyone within the room as well as their role. If you would like to add people select the fourth circle on the dashboard that says "+Add People"
Once you have added a participant to your room you can edit their role by making them either a Moderator, Participant, or Explorer.
Moderator: Can change all room settings.
Participant: Contribute content, view all walls.
Explorer: Limited to assigned missions. Explorers are "mission-only" users. They see only missions assigned to them and the content they upload.
Note: To invite external Explorers or Guests to participate in the Mission, your account will need to be flagged by the community manager that allows you to "invite community guests via email". All individuals invited from the room level are flagged as "guests" in the community.