Marquee select across groups
I'm surprised this isn't a feature already, but marquee-select (click and drag) to select multiple layers regardless of what group they are in. At present doing so will select standalone layers and whole groups, meaning I need to de-group first to then do what I want, or leave grouping until the last possible moment in a design.
Steven Ackerman commented
The thing about this is, Sketch and Figma users who do heavy-duty work can't do so quickly in XD. Click-selecting every element is not an option.
Thanks for making Feature Requests!
Currently, you can select individual items across Groups using Cmd-select in Layers panel, so no need to ungroup-then-regroup.
We'll take a look at providing same functionality with marquee-select.