If you would like to compare the evolution of a specific KPI between two periods of time the Line Chart widget offers you this possibility. The process would be as follows:
When selecting the period of time in a Line Chart widget there will be check box labeled "Compare to..." , this check box, when clicked, will give you 4 comparison possibilities:
1- Previous period: it will compare the current select period of time with the immediate previous period of time of the same size.
2- Previous month: it will compare the current selected period with the results you had the same days the month before.
3- Previous year: same behavior as with the option "Previous month" but this time the comparison will be with the results you had the same days last year.
4- Custom: you'll select manually the period of time that will be compared against your current selection of dates.
The full process is shown below:
You can select a maximum of 4 KPIs per widget when using comparisons.