Please follow the below step to create group ledger:- 

Step 1:- Login in to the Accounts Section

Step 2:- Click on the "Settings" 

Step 3:- Click on "Add GL Group" option in "System configuration"

Step 4:- Select Type of account as "GL Group"

Step 5:- Select the Parent Group name from the dropdown menu for the GL Group you want to create

Step 6:- Type the GL Group name

Step 7:- Click on "Add Account" at the bottom

Please note GL Group helps in grouping of several GL Accounts or groups for the purpose of display in various reports in Accounts