Comparing the values of a certain attribute with its previous period across various visualizations can be done using the compare periods feature in HappyFox BI.

This can be done by simply clicking on the ‘Compare Dates’ button on the top right side of the page.

You can then select the period you want the visualizations to be compared. 

Visualizations that are capable of displaying comparison will automatically start displaying values for the current and selected compare period.

This feature is available only for Enterprise plan users.