A working dashboard needs both a saved action and a useful response. Decide what should change when the reader selects a mark, then choose the action that owns that state. A parameter holds one value. A set holds a membership list. A URL action resolves an address, while a Show/Hide Button changes an object's visibility.
These tasks use Harbor Bikes and Northwind Help Desk rather than the regional sales examples. Read the starting state, particularly the members already in a set. Adding a member and assigning a new selection can look identical when the starting set is empty, so the tasks deliberately begin with reviewed members.
Test clearing and triggers too. A Menu action should wait for an explicit command, and a Select action should respond to a click. Keep optional instructions recoverable with a button. Removing an object isn't the same as hiding it.