It might not be as quick and easy as the old way but it’s still possible.
In the navigation on the right hand side, select ‘Behaviour’ and then select ‘View all campaigns’ at the bottom right of the source medium table.
This will then load you the source / medium report when you can switch out the primary dimension. Select from the drop down options ‘Default Channel Grouping’
Once loaded you can then bring in a secondary dimension by selecting the plus sign…
Then selecting ‘Acquisition’ and then ‘User source/medium’
And voila – you have your Default Channel Groupings broken down by Source / Medium.
Note this is also possible using the Exploration Tool.