If you're an owner or admin on your Ethnio account, you will see a team section under account >> team. Head there and choose to either share everything with everyone, or assign specific permissions to screeners and/or folders. Folders can be handy because you can easily drag and drop screeners into that folder, and know they will be shared automatically without having to mess with permissions.
See below for multiple admins on your account.
Step 1: Choose Permissions Style
Most customers share all screeners with all team members, but there are lots of cases where you need to restrict access and choose permissions for each team members. Flip this toggle to "off," to edit permissions
Step 2: Click Permissions
If you want to edit individual permissions, click the permissions link after you've flipped the toggle above to "no"
Step 3: Use Folders (Optional)
As a shortcut, you can create folders by team or group and drag screeners into that folder as a way of not having to open up permissions. From screeners >> overview, create folders and drag screeners in there you wish to share with specific team members.
That way you only have to give someone access to a folder once from Team >> Edit Permissions, and in the future any screeners you drag to that folder will be shared with team members you gave access to view/edit:
Multiple Admins (Pro and higher plans)
For certain plans, you can specify multiple admins that will have access to all screeners. This way you can limit permissions for team members, and easily grant full access to account admins.