Hi Anitha,
You can form groups in tableau manually or by selecting items from the visual.
By selecting on the visual ->
Select the group of items then click on the group icon.
![](https://www.edureka.co/community/?qa=blob&qa_blobid=11378661327090419557)
Now Edit the groups and items within them.
Now place the group in the visual, and also the items in the group on the shelf.
From field ->
![](https://www.edureka.co/community/?qa=blob&qa_blobid=13358139800691342355)
Now go to analytics pane and drag the totals and place in sub-totals followed by grandtotals.
![](https://www.edureka.co/community/?qa=blob&qa_blobid=16115395614344405532)
![](https://www.edureka.co/community/?qa=blob&qa_blobid=4409955580427498047)
Hope it helps.