Currently I have one group and I see around 20 ledgers name on summary page I want to see only group balance with an option to open it further to see details.
You have not provided enough information to answer your question definitively. Basically, however, groups on the chart of accounts to not absorb accounts assigned to them. They only control where those accounts are displayed and provide subtotals for them. What you want might be possible with custom control accounts. But first, you need to describe what you are trying to do in greater detail, including the types of accounts you are referring to.