Within Float you can group multiple categories together to show only a top line figure in the cash flow. To do this select 'Manage table layout' (from above the left side of the main cashflow table) and choose the ‘Create group’ option which will allow you to name and choose whether the group is cash in or cash out.
Once created you can then add accounts to the group. To do this click into the relevant account from the list in 'Manage table layout' and you will see the option to assign it to a group.
When an account is added to a group it will then show as part of that group in the main cash flow. When the group is closed only the group total will display however clicking on the group will open it to reveal the accounts contained within it.