title: To have unique group name within Account, having sub-accounts
body: <p>DB design for the below usecase:</p>
  
  <p>Account will have multiple sub-account. Account and sub-account will also have groups within it. The group name should be unique within account, How can have DB design for this?</p>
  
  <pre><code>
  Account (table)
  |------&gt; Group (table)
            |----&gt; GroupA (Value for Group table)
  |------&gt; Subaccount1 (table)
            |----&gt; Group (table)
            |      |----&gt; GroupA (Value for Group table. This should not be allowed).
                   |----&gt; GroupB (Value for Group table.)
            |----&gt; Subaccount2 (table)
                   |-----&gt; Group (table)
                           |-----&gt; GroupB (This should not be allowed, as the parent subaccount has it in its group)
  </code></pre>