Setting up custom permissions on SharePoint

Creating a new permission level

1- Open the library on which you want to apply the custom permissions.

2- Click on gear icon and select site permissions

3- Click on Advanced permissions settings

4- Click on Permission Levels

5- Select Add a Permission Level

6- Assign the permissions as per requirement

7- Save the permissions

Assign the Custom Permissions to a Group

1- Open the library on which you want to apply the custom permissions.

2- Click on gear icon and select site permissions

3- Click on Advanced permissions settings

4- Click on Grant Permission

5- Enter user and group and select permission to assign

6- Click on share