You have to two options to filter the data from Analytics area.
The first one is from the Filters area. Simply select the filter(s) you need and all the charts from the dashboard will match your choices. More info on filters can be found here.
The second option is to filter by Segments. You can visualize the data and get insights for all your mentions, or only from a specific segment. You can find more info on segments here.
You can create as many segments as you need, anytime. By default, even if no segments were created, you'll have the possibility to select from the following segments:
All mentions: no segment or filters applied to the data you get in BrandMentions' Dashboard.
Important mentions: See all mentions that have a performance score higher than 30.
Positive sentiment: See all the mentions that have a positive sentiment analysis.
Negative sentiment: See all the mentions that have a negative sentiment.
Once you select a segment or metrics to filter the data, all the charts will be updated based on your options.