You have two options, considering your employee’s lab notebook represents their whole sciNote account (= employee’s team) or an individual project within your team.
In the first case, each individual employee can invite you to their team. After that, you are only able to see the projects that are set as public.
If you want to see their private project, they need to invite you to it and assign you a role. To decide which role might suit you most, watch the video tutorial Managing User Privileges and Roles.
Alternatively, you can invite your employees to your team, where they can create their projects. Thereafter, they have to invite you to a project and set it as Private, so others cannot view it. Since you are the Creator of your team, you are an Administrator by default, which means you can see all private projects. For easier understanding see the GIF below.