The first step towards controlling what an Admin can do or see is to create a Role with specific permissions. Every Role has a set of permissions tied to it, so you can reuse the Role for multiple Admins. To edit an Admin User's role and/or permissions, see below:
Access Admin User's Profile
Go to the Admins Page (My Company > Users > Admins)
Edit an existing Admin's permissions by clicking on the pencil icon beside the Admin User's name
Add a new Role
Scroll down to Role & Assignments. Click on that Admin's Role to show the Role Management window.
Click the current role and then select the blue plus button
Add a name for the new Role and select which permissions you want to provide the Admin. There are 28 permissions available for Admins. These permissions are described in more detail in this support article.
Click Save and assign the role to the Admin User by checking the box beside the Role.
Edit Permissions
Scroll down to Role & Assignments. Click on that Admin's Role to show the Role Management window.
Click the current Role and select or deselect the permissions.
Select Save to save the new permission (see Important Note below).