> For the complete documentation index, see [llms.txt](https://help.bizmachine.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.bizmachine.com/en/search-and-filtering/segment-as-a-filter.md).

# Segment as a filter: include or exclude a whole segment

How to use an existing segment as a filter when building a new segment, to include or exclude a group of companies defined by any criteria.

*Updated: 7 October 2026*

When you build a segment, you can use another segment as one of the filters and choose whether to **include** or **exclude** the companies from it. That way you can exclude a group of companies defined by any filters, not only companies with a specific label.

*This article describes the Segment as a filter feature. The basics of building segments and an overview of all available filters are in* [*How to create a segment in Prospector*](/en/search-and-filtering/creating-segments.md)*.*

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### What is Segment as a filter for?

Excluding by label (the **My labels (excluded)** filter) works only for companies you add to the label by hand. If you want to exclude companies that meet other criteria (industry, technology, number of people in a department), build a **helper segment** for them and then include or exclude it in the target segment. Unlike a label, the helper segment needs no manual upkeep: it always contains the companies that currently match its filters.

The feature is also useful when you want to exclude a wider group than you can mark with a label by hand, for example a whole holding, a region or a group of connected companies.

**When it is useful:**

* Exclude a whole industry (for example, manufacturing by NACE business category)
* Target only companies with a specific department, or only those without one
* Target companies without an e-shop, or only those with one

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### How do I use a segment as a filter, step by step?

1. **Prepare the helper segment.** Create a segment that contains the companies you want to include or exclude, for example a segment called `Manufacturing` (the **NACE business category** filter) or `Companies with a marketing department`.
2. **Open the target segment**, or [create a new one](https://prospector.bizmachine.com/v3/en/datasets/cz/search?sfc=true).
3. Click **+ Add filter** and open the **Labels & Segments** category. Choose **Segments** if you want to include the helper segment, or **Segments (excluded)** if you want to exclude it.

   ![The filter menu with the Labels & Segments category expanded and the Segments and Segments (excluded) items](https://247275268-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FYkl7SJ14Nk0vzhVx7upl%2Fuploads%2Fgit-blob-fbdd3704f8a4ed3ec1505aef704653660d177a4b%2Fsegment-jako-kriterium-vyber-filtru.png?alt=media)
4. **Choose the specific helper segment** from the list.
5. Add any other filters you need, then save the segment.

{% hint style="info" %}
Segments are dynamic. As soon as you edit the helper segment, every segment that uses it as a filter updates automatically.
{% endhint %}

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### Examples: excluding an industry, a department or e-shops

#### Exclude an industry

Prepare a segment called `Manufacturing` (the **NACE business category** filter). Exclude it in the target segment, and the target segment keeps only companies outside manufacturing.

#### Target companies with a specific department, or without one

Prepare a segment called `Companies with a marketing department` (the **Department and role** filter).

* The **Segments** filter: you get only companies that have a marketing department
* The **Segments (excluded)** filter: you get only companies without a marketing department

#### Exclude companies with an e-shop

Prepare a segment called `Companies with at least one e-shop` (the **E-Commerce** filter). Exclude it in the target segment (for example, `B2B prospects without an e-shop`), and only companies without their own e-shop remain.

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### Can a helper segment contain another segment?

No. A segment you use as a filter cannot itself use another segment as a filter. Nesting works only one level deep.

{% hint style="warning" %}
If a segment itself contains another segment as a filter, it appears in the menu as unavailable (greyed out) with an explanatory message. Choose a segment that does not refer to any other segment instead.
{% endhint %}

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### Frequently asked questions

**Can I use a segment a colleague shared with me as a filter?** Yes. You can use any segment you see in your Prospector as a filter, both the segments you created and the ones colleagues have shared with you.

**Can I use a segment as a filter if it already uses another segment as a filter?** No. Nesting works only one level deep, so Prospector shows such a segment in the menu as unavailable.

**How is this different from the My labels (excluded) filter?** My labels (excluded) excludes only the companies you have added to the label by hand. A segment filter excludes every company that currently matches the helper segment's filters, so you do not have to maintain anything.

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### Related articles

* [How to create a segment in Prospector](/en/search-and-filtering/creating-segments.md)
* [How to exclude existing customers and avoid duplicate work](/en/lists-and-export/excluding-existing-customers.md)
* [Labels as a workflow system: managing your pipeline](/en/lists-and-export/labels-as-a-workflow.md)