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# Let readers filter, drill down or see rows behind a chart

> Choose what viewers can do when they click a Mammoth dashboard chart: filter the board, see the rows behind a bar, or drill down from region to country.

The **Readers can** section of a chart's edit panel controls what viewers of the published dashboard can do when they click that chart: filter the board, see the rows behind a bar, or drill down a level. Click the chart in the dashboard editor and scroll to **Readers can**. Anyone who can edit the dashboard sets these switches; seeing the rows is for signed-in viewers only.

## Which charts readers can click

The section appears on charts readers can click: Bar, Bar (H), Donut, Stacked bar, Grouped bar, Treemap, Scatter, Bubble, and Line charts over dates. It reads: "Readers never see more than this. Turn these off to make the chart view-only."

| Switch | What readers get | Who can use it |
|---|---|---|
| **Filter the board** | "Click a bar to filter every chart on the page" ("Click a mark…" on other chart types). On by default. | Anyone who can view the dashboard |
| **See the rows** | A list of the records behind the bar or slice they click. "Signed-in viewers only. Row security applies." | Signed-in viewers only |
| **Drill down** | The chart redraws one level down, such as from region to country, or from year to quarter. | Anyone who can view the dashboard |

To make a chart view-only, turn all three off.

## Let readers click a chart to filter the board

**Filter the board** is only offered when the chart's **By** field is also one of the dashboard's filters. Otherwise the section says so, for example "Add Region as a board filter to let readers filter by it." See [Filters](https://mammoth.io/docs/learn/dashboards/filters/) to add one.

## Let signed-in readers see the rows behind a chart

When **See the rows** is on, the section shows which columns readers get: "Rows show the chart’s fields and up to 4 key columns from your data", sorted by the chart's measure, largest first.

To choose the columns yourself:

1. Click **Edit** to open **Columns readers see**.
2. Tick the columns.
3. Click **Done**.

**Use the suggested columns** goes back to the default.

What readers can and can't see:

- Readers see at most 12 columns, counting the chart's own fields.
- Protected columns are never offered or shown. Neither are columns that look like contact details: an email, phone number, postcode, tracking number or person's name.
- The viewer's row-level security applies, so each reader sees only the rows they're allowed to.
- Rows aren't available on public links, in embeds, or to anyone who isn't signed in.
- In the editor, you can preview the rows whatever the switch says.

## Let readers drill down from one level to the next

There's one drill path per dashboard, so you don't pick it per chart. The section shows the path. It adds "(found in your data)" when the path follows a hierarchy in your columns. Otherwise it uses the date path (year → quarter → month → week → day).

Drilling works on public links and embeds too, because it only shows totals. Row-level security still applies.

## What readers see when they click a chart

On the published dashboard, clicking a bar or slice opens a short menu with the actions you switched on:

| Action | Example | What happens |
|---|---|---|
| **Filter the board to** the value | **Filter the board to Europe** ("Every chart on this page changes") | Filters every chart on the page. If the filter only reaches this page, it reads **Filter this page to Europe**. |
| **See the rows behind** the value | **See the rows behind Europe** ("Opens a list next to the board") | A side panel lists up to 500 rows. It says "Showing the first 500 of" the total when there are more. For a plain sum, it confirms the rows add up to the same number as the bar. |
| **Drill into** the next level | **Drill into countries in Europe** ("Only this chart changes") | The chart redraws a level down. A breadcrumb such as "All regions › Europe" leads back up. |

For the full viewer experience, see [What viewers see](https://mammoth.io/docs/learn/share-and-export/what-viewers-see/).

## Limits

| Item | Limit |
|---|---|
| Columns readers see in the rows | Up to 12, counting the chart's own fields |
| Suggested key columns | Up to 4 |
| Rows listed in the side panel | Up to 500 |
| Drill paths | One per dashboard |

## Troubleshooting messages readers see

| Message | Cause |
|---|---|
| "Rows are turned off for this chart." | **See the rows** is off. |
| "Drilling is turned off for this chart." | **Drill down** is off. |
| "Rows aren't available for this part of the chart." | The reader clicked the "Other" bar or a calculated band. |
| "There is nothing below this level." or "You can't drill into this part of the chart." | The drill path has no further level here. |
| "This board is still updating." | The dashboard is refreshing. Try again when it finishes. |

## Related

- [Set up a chart](https://mammoth.io/docs/learn/dashboards/edit-a-chart/): the chart's fields and calculated bands.
- [Filters](https://mammoth.io/docs/learn/dashboards/filters/): add the board filter that **Filter the board** needs.
- [Publish and share a dashboard](https://mammoth.io/docs/learn/share-and-export/share-a-dashboard/): sign-in, public links and row-level security.
- [What viewers see](https://mammoth.io/docs/learn/share-and-export/what-viewers-see/): the reader's side of the dashboard.
- [Chart style, annotations and captions](https://mammoth.io/docs/learn/dashboards/chart-options/): the other chart options.

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Source: https://mammoth.io/docs/learn/dashboards/chart-reader-actions.md · Updated: 2026-11-08