This post explores an approach for implementing hierarchical selections in Tableau which can be used for filtering and highlighting.
Creating a Selection Panel with Parameter Actions
This post walks through how to create a selection panel using parameter actions, storing all selected items in the same parameter and giving feedback when the max number of items have been selected.
Drawing on Dashboards
Using a parameter as data source, this blog shows how you can draw sequential points over a grid or on a map with spatial points.