Relating Elements between categories in Layer allows you to leverage the power Layer to transform and act on your data. Imagine that you have two categories in an employee directory project - Employees and Departments. Employees contains individual elements for each employee working in your firm or company, and Departments contains elements for each team or group that employees are divided into. Layer’s flat data structure means that the implicit link between these two categories isn’t automatic - it must be specified by the user. In turn, Elements retain their original Category structure and classification while also being cross-linked to Elements in other Categories.

In the employee directory example above employees have departments, and departments have employees - the relationship can be viewed and acted upon from either side. Relationships between categories can be either one-to-one, one-to-many, or many-to-many.

How it Works

There are a few different ways to relate elements between categories in Layer - each with their pros and cons. Read on to get a better idea of how to apply these methods in your project.

Related Element Field

A Related Element field is a manual or automated link between two categories. When configuring a related element filed in one category, you specify the other category to which it will connect.

In the example above, you would create a related element field in the Employees Category configured to point at the Departments Category. When editing Employee elements, you would have the option to select a Department to tie to that particular Employee.

That’s it! A link has been made between the two categories and data can be added. For more information, see the Related Element field page.

Spatial Relationship Field

A Spatial Relationship field is an automatic link between two Model Categories.

Lookup Field

Layer V4 Update: Lookups are now a part of Relationships & Formulas

Displaying values from related categories

Once two categories are connected with a related element, you can display information from one category inside another.

For example, if each Product is linked to a Vendor, you can show the Vendor’s website or email directly in your Product table.

To display a related value:

1. Open Edit Fields in your category.

2. Click Add Field → Relationships.

3. Choose the existing relationship (for example, Vendor).

4. Select the property you want to show (for example, Website or Email).

5. Click Create Field. The value will now appear automatically for each related item.

This replaces the old Lookup Field feature. You can now pull values directly from any Relationship you’ve created, whether it’s Manual, Automatic, or Spatial.

Tip:

If you need to calculate or combine data from a relationship (for example, count items or sum totals), use a Formula field instead. Lookups are a native variable in Layer Formulas.