Time, Level and Currency filters are already in the Context Filter. Additional filters such as Level Attribute, Dimension or Dimension Attributes can be added to the filter. In the charts below, I would like to filter the data by Product, which is a Custom Dimension.
To add an additional filter:
Open the Perspective and select Edit.
To activate the Perspective Settings, click on the Perspective Name which is located on the top left.
In the right pane, select Data Settings.
Click on Context and select from the elements.
I selected Dimensions and selected Product:
The Product Dimension now appears in the Context Filter. I can now click on the drop-down arrow next to Product and select the desired value from the list.