Cascading Filters
Let one filter narrow the choices in another, control the direction, and understand what viewers see.
Cascading narrows the choices in one filter based on selections in others. Pick United States in Country and the City list shows only US cities. It never changes which cards a selection filters; that is card mapping.
Cascading is on by default for regular dashboard filters. Most dashboards need no setup.
The three modes
Open a filter's settings, then set Narrow available options by on the Basic tab.
| Mode | Effect | Use when |
|---|---|---|
| All applicable filters (default) | Every related filter in scope on the current sheet narrows this list. Unrelated filters are ignored. | Related filters should narrow each other in both directions. |
| Selected filters | Only the filters you check narrow this list. | You want a fixed parent, or a one-way flow. |
| None | Other selections never narrow this list. | The list should always show every choice. |
With All applicable filters, Country narrows City and City narrows Country. Filter order in the toolbar does not create a parent-child relationship.
Make a cascade one-way
To have Country narrow City without City narrowing Country:
Set Country to None
Open Country's settings and choose None under Narrow available options by. Choose Accept.
Point City at Country
Open City's settings, choose Selected filters, and check Country. Choose Accept.
Both filters still apply their selections to their configured cards. Only the choice lists changed.
Selected filters picks which selections to consider. It cannot connect data that is not related; see When narrowing needs a relationship.
What viewers see
| Situation | The menu shows |
|---|---|
| Another selection narrowed the list | Narrowed by Country above the options. |
| No choices remain | No options match the current filters. Change the related selection to see other choices. |
| A selected value no longer matches | A note that the value has no matches under the current filters. The value stays selected until the viewer changes it. |
| A selected dependency cannot be applied | The reason, and for supported cases a Show options without Country action. |
Selections are never cleared for the viewer. If Paris is selected and Country changes to United States, Paris stays selected and keeps filtering its cards until the viewer replaces or clears it. A value missing from the visible page of choices is not treated as invalid; menus search and load more on demand.
Show options without Country browses the broader list for that dependency only, labels the result, and offers Undo. It does not change the selection, the cards, or the saved dashboard, and it never bypasses permissions or covers a database failure.
When narrowing needs a relationship
Semaphor narrows only along relationships it can prove.
Choose what makes an option relevant
Store and Category can relate through more than one dataset. Categories stocked at a store come from Inventory; categories sold there come from Sales. Those are different answers, and Semaphor will not pick one for you.
For semantic filters, set Limit choices to values present in on the Basic tab to the dataset that carries the meaning you want. You need it whenever two filters connect through a fact or bridge dataset rather than a direct relationship.
This setting also applies with None: a Category filter limited to Sales offers categories present in Sales while ignoring the selected Store. None ignores other selections; it does not remove this restriction or any data access permissions.
Custom SQL filters
A filter whose choices come from custom SQL is narrowed by its own query. The modes above do not apply; use the filter helpers in the SQL to include or omit other filters. See Filters in SQL.