You can create pie charts with the Pie Chart widget. Select metrics from the left menu to add new diagrams (e.g. here two metrics are selected, which gives us two circles).
You can also switch to the data table itself (and back to pie chart) by pressing the icon at the top right corner of the widget screen (left one near the gear icon).
This widget provides a number of options for customization, which you can see at the left of the Add widget window. You can enter a new name for your pie charts in the rounded rectangle on the top of the left menu, and define a time range, which will work in the same way with the reports one, but affects only this widget.
There are two options for time range: use the same time range as the rest of the report or define a custom one. Custom time range allows you to define dates manually or with a list of pre-defined options.
Pie chart also has decimal places setting or each selected metrics. Press config near the metric name to open this menu.
This widget supports a filtering function. You can select the filter checkbox on the top of the widget customization screen and press filter caption (or the plus sign near it) There are three input fields for each filter. The first one is a drop-down menu, where you can select the variable name for filtering. The second dropdown sets the rule for including or excluding cases. It has two variants: for text and numerical variables.
Texts can be filtered for containing or not containing a set of symbols, having an exact match with this set or having at least one item from the list given. Numbers can be filtered by simple comparison (more than x, less than x, not more than x, not less than x). You can always combine few different filters by adding a new to the already existing one (by pressing filter caption or the plus sign again)