Using the powerbi filter for custom visual

Hi, im pretty new to powerbi. im trying to create a custom linechart, while only displaying the selected column in the powerbi filter.

The problem is, i don't know how to use that filter i created on the report.

As soon as i select more than one column, it just sums up all the values underneath this option to one column, but i want to have a new column for every single selection i make.