You can assign user group to employees individual and also in bulk way, please follow below steps:

1) How to assign user group for individual employee ?

Step 1: Search for that employee and below top menu you will find "Edit user" Button.

Step 2: Click on "Edit User" button and you will find "Role" field in which you can add of which user group that user belong.

2) How to assign user group for all users ?

Step 1: Go to top-right-hand side profile icon -> Uknowva Configuration

Step 2: Go to left-hand-side-menu you will find "USER MANAGER" menu

Step 3: Click on "Import user" button

Step 4: Download the CSV file and add user group of all users.

NOTE: Please make a note that if users has more than one user group then add User Group by "| separated".

Step 5: Then upload that sheet from your local machine to uknowva system.