Here's how you can decide which user will be the administrator of a group, and set each administrator's permissions.
Click on main menu three-lines symbol in the top-left corner, to open it, and then choose Manage admins (1) from the dropdown list.
To create a new admin, click Add Admin (2).
Type the new admin's Email, First Name, and Last Name, and choose their Role (3) from the two available options:
Group Admin - View: Has permission to view group data but cannot edit them.
Group Admin - Update: Has permission to both view and edit group data.
From the Select Groups (4) drop-down list, choose the group(s) you want to assign to your new admin.
When you are done click Save (5).
Note: Upon creation, the new group admin receives an automated email with the necessary information, including a link where they can set up a password for signing in to the web app.