In budget reports, the display depth of accounts can be set in de the report options. It would however be useful if (sub)accounts could be collapsed or extended by clicking on the account on the higher level. Then there is no need to open the options first and regenerate the report.

Same goes for charts like the expense charts: when the report is generated with for example the second sub-account level, the user should be able to click on a part of the chart to open the (3rd level) subaccounts of that account.