hi @SnailFuji
I am afraid there is no way to set the value of the filed which is not being used in the line chart into the parameter you created. so you can’t pass the value using URL action. the only way I can think of is to have another table to show the tooltip values which you would like to use for URL action, by filter action from the line chart. from the table, you trigger the URL action.
kind regards,
Wakana