Content Block fields
Create nested field layouts that can be reused in other element types’ field layouts, with the new “Content Block” field type.
Collapsible source headings
Source headings within element indexes are now collapsible.
Grouped entry types for Matrix fields
It’s now possible for entry types to be presented in groups within Matrix fields.

Expand or collapse all blocks for inline-editable Matrix fields
New “Expand all blocks” and “Collapse all blocks” actions are available for Matrix fields set to the “inline-editable blocks” view mode.
Search for entry types within Matrix fields
When a Matrix field has five or more than five entry types, a search input is shown within entry creation menus.
Inline element search and creation for relational fields
Relational fields with a single element source can now show a search input for quickly selecting elements, without having to go through the element selection modal.

Entries fields with a single section source and without a selection criteria condition also support inline entry creation.