Roles and permissions are a way of controlling the access and actions of administrators and users in Horizon. By default, Horizon provides two predefined roles: Administrators and Read Only Administrators. However, a high-level administrator can create custom roles with specific privileges to suit different needs and scenarios. To create a custom role, the administrator needs to follow these steps:

In the navigation pane under the Settings section, click on Administrators > Roles and Permissions.

In the Roles and Permissions page, click on Add.

In the Add Role pane, enter a name for the role in the Role Name text box.

In the Privileges section, select the checkboxes for the privileges that you want to assign to the role. You can expand or collapse the categories to view or hide the sub-privileges. You can also use the Select All or Deselect All buttons to select or clear all the privileges in a category.

Click on Save to create the custom role.

The custom role will appear in the Roles and Permissions page, where you can edit or delete it as needed. You can also assign the custom role to users or groups in the Users and Groups page.Reference: [Create Custom Roles] and [VMware Horizon 8.x Professional Course]