Although the overall trend within a metric might provide an initial answer to the question you have asked of it, often greater detail is required to move the metric forward and to gain greater insight. In Plandek one quick way to achieve that greater detail is the user of Breakdowns.
Breakdowns are available within Metric Settings ⚙️. Different Metrics will have a different list of available breakdowns, based on the nature of the metric, but any Ticket based metrics can be adjusted (by Plandek) to include any field you require for your team or organisation.
Selecting from a variety of relevant fields you are able to breakdown each metric to see a total or over time comparison. When viewing over time you have the option of Multi line, Stacked chart, Grouped chart or 100% Stacked chart.
Please also remember that when adding a breakdown by the field that allows multiple values (e.g. Labels or Components in Jira), that the sum of the individual breakdowns will be greater than the overall total. This is simply because a single ticket can be duplicated across the multiple values relevant to it.