I need to display the second level details for table rows.. kind of an accordion view for every record which displays further details upon expanding the same. It may or may not require additional API calls on row expansion. Design is not rigid and can be altered based on the options available ootb, eg. modal popup with details, preview pane alike on the right with details, etc.
@VibhorAgarwal No such option OOTB for your version. You could make a repeating layout with a nested field group that is collapsible. It gets you half-way, but the rows will be always expanded on load. In Pega '26 there are plans to let you configure collapsed-on-load behavior for lists.
For this type of “second-level details per row” requirement, the practical OOTB options are Show additional details on the table row, open a modal/local action from the selected row or open a preview / slider pane on the right side.
The preview pane / modal pattern is often a better fit than trying to force an accordion behaviour.
If your table configuration supports Show Additional Details, that is the simplest option. If row expansion is not available/sufficient, use a Preview or Modal pattern instead of accordion rows. This is usually more consistent with Constellation UX and easier to maintain. A modal or preview pane is generally the better choice, because you can fetch the extra details only when needed rather than loading everything in the initial table payload. If the business insists on true accordion style interaction, then this may require a custom DX component, because row-level interactive expansion inside dynamically generated Constellation tables is limited OOTB