Dynamic related lists in Lightning App Builder
Key Takeaway
To show a related list with only certain records, use the Dynamic Related List–Single component in Lightning App Builder and add a filter. A related list added from the page layout editor can't have custom filters.
A dynamic related list is a related list that you build and configure directly in Lightning App Builder, using the Dynamic Related List–Single component. You don't use the page layout editor for it. You can filter the list, rename it, and choose its columns, sort order, and actions, so users see only the related records they need.
What a dynamic related list adds
The Dynamic Related List–Single component adds one related list to a Lightning record page. You configure it in the properties pane. Before this component existed, you had to go to the page layout editor to change a related list's columns, sort order, or actions.
Filtering is what sets it apart. The Dynamic Related List–Single component is the only way to put custom filters on a related list, because a related list added from the page layout editor can't have custom filters.
Priya manages support for key customers. On the Account record page, she wants a Cases list that shows only cases with a Priority of High. She can't filter a related list from the page layout editor this way. So she adds a Dynamic Related List–Single component, picks the Cases related list, and adds a filter where Priority equals High.
You can place two or more dynamic related lists with different filters on the same object. Give each list a descriptive "Related List Label" so users know which records they are seeing. For example, an Account page could show one Cases list filtered to High priority and labeled High Priority Cases. A second Cases list could be filtered to Low priority and labeled Low Priority Cases.