On the dashboard, click on the FILTER button on the top right corner. This will open a filter interface where you can input various conditions for your dashboards.
You can select a date, channels, countries, languages, sentiments, and status of the messages (MESSAGE PROPERTY) as per your requirement and the graphs will be generated in accordingly to the filter conditions.
In addition to the options provided in the FILTER, you can also do the sub keywords search from the SUB QUERY filter options. Just provide the keywords with (OR, NOT or AND) logic operators to filter the data.
*NOTE: MESSAGE PROPERTY are the list of various stages through which messages needs to go through. For example, when a message is assigned to team members it is in ASSIGNED stage, when the member responds to the message it is in REPLIED stage and when he/she closes the case it's in CLOSED stage.