Collapsing the hierarchy in a story can help limit the refresh time, as it reduces the amount of data that needs to be processed and displayed at any given time. By presenting data at a higher aggregation level initially, you can improve performance and allow users to expand specific sections of the hierarchy as needed for more detailed analysis.
Reference:
SAP Analytics Cloud Help Documentation: Improving Story Performance
SAP Analytics Cloud User Guide: Managing Data Hierarchy for Performance

When using an input control to filter data in a SAP Analytics Cloud story, the filter is applied at the Page level. This means that the selected filter criteria will affect all the components (tables, charts, etc.) on that particular page, allowing for a cohesive and consistent view of the data filtered according to the chosen parameters.
Reference:
SAP Analytics Cloud Help Documentation: Filtering Data with Input Controls SAP Analytics Cloud User Guide: Page-Level Filtering in Stories

To display differences between measures in a chart within SAP Analytics Cloud, you can use the Variance feature. Variance helps to highlight the differences or gaps between two data points or measures, making it easier to identify trends, outliers, or areas requiring attention in visual representations like charts.
Reference:
SAP Analytics Cloud Help Documentation: Variance Analysis in Charts
SAP Analytics Cloud User Guide: Displaying Measure Differences Using Variance