dropdown to change the filter data, so you need a flag to know which one is selected. (flag = false)
on drop down change use microflow to update the flag change.(item selected with flag = true)
using data view to cover line chart with a source create by microflow, then on the line chart you need filter with the flag has been updated (flag = true)
Use an on change microflow. Based on the value you can then set the value for the condiitional visibility that shows the the line chart.
Where do I put the microflow in the drop down or in the line chart?