Filters

Filters narrow a layer down to the features you actually want on the map. Instead of bundling everything together, you decide which fields people can filter on, what the controls look like, and which views expose them.

Filters live on the layer itself, in the layer detail panel under the Filters tab. Once a filter is set up there, you can decide later, per view, whether viewers see it as a full control, a simple toggle, or not at all.

Turn a field into a filter

When you import data, Topologis reads its columns and figures out a type for each one (numeric, categorical, date, text, or boolean). Open the layer, switch to the Filters tab, and you’ll see that list as a checkbox group titled Filter Data.

To set up a filter:

• Tick the checkbox next to a field to enable it.
• Adjust the controls that appear underneath. The shape of those controls depends on the field’s type.
• Click Save Changes when you’re done.

There’s no separate “filter” object to name or manage. The field name is the filter. If you stop using a field as a filter, untick its checkbox and the control goes away.

Filter types

Topologis matches the control to the data, so each field type gets its own UI:

• Numeric: counts, scores, prices, measurements
• Date: timestamps and dates
• Categorical: fields with a known set of values, like region or status
• Text: free-form strings like names, codes, or descriptions
• Boolean: true/false flags

The next sections walk through each one.

Numeric fields

Numeric filters show a histogram with a draggable range. Drag the handles to set a minimum and maximum, and the map keeps only the features whose value falls inside that window.

Use this for anything continuous: population, revenue, elevation, score. The histogram also doubles as a quick read on the data. If most features cluster at the low end, you’ll see it before you start filtering.

Date fields

Date filters work the same way as numeric ones, but with a date range. You’ll see a histogram of when features fall on the timeline, and you drag the handles to pick a start and end date.

This is the right choice for anything time-bound: incident dates, build years, sales periods. If you want viewers to step through time rather than slice it, look at time-series mode in Layer Render Modes instead.

Categorical fields

Categorical filters are a multi-select. You’ll see every distinct value the data contains, and you tick the ones you want to keep.

Reach for this when the field has a stable, finite set of options: country, status, asset type, department. If the field is more open-ended (like a free-text description), use a text filter instead.

Text fields

Text filters give you a search box and an operator. Pick how to match, type the query, and decide whether casing matters.

The available operators are:

• Contains
• Does not contain
• Equals
• Does not equal
• Starts with
• Ends with

Contains is the everyday choice. Reach for Starts with or Ends with when prefixes or suffixes carry meaning (a country code, a file extension). Toggle Case Sensitive only when you actually need it; most string data is messier than people expect.

Boolean fields

Boolean filters are the simplest of the bunch: pick True or False. The map keeps only the features that match.

Use this for flag-style fields like is_active, verified, or archived. If a field could meaningfully have more than two states, model it as categorical instead so people can pick which states to include.

How filters behave in views

Filters live on the layer, but views decide what your audience can do with them.

When you configure a view, each layer’s active filters appear nested under that layer in the view’s Layers tab. For each one you have two switches:

• The power toggle turns the filter on or off for that view. Use this when a filter is useful in the editor but not relevant to a particular published map.
• Add UI control decides whether viewers see the filter as an interactive control. Leave it off and the filter still applies; viewers just don’t get to change it. Turn it on and they see the same kind of slider, multi-select, or search box you used.

This separation is the point of views: one project can power several published maps, each with a different mix of filters that are visible, hidden, or off entirely. For more on the surrounding view model, see Views.