Add a custom dimension

A custom dimension is a custom field that sorts your data into categories you define, built from rules that read fields a dataset already has. This page covers building one, saving it, and confirming it groups your data the way you expected.

Before you start

Custom dimensions live in Workspace settings → Data model, which is open to workspace admins. If you don’t see it, ask an admin to add the field for you.

Decide two things first: which dataset the dimension belongs to, and which field its rules will read. A rule can read text, number, country, and true/false fields. Dates and metrics aren’t available to it, and it can only read custom fields that sit above it in the field list.

Create the dimension

1. Open Workspace settings → Data model.
2. Select the dataset in the left panel. Its fields appear grouped by category.
3. Select + Dimension.
4. Give it a Title of up to 64 characters. Give it a Category too: the group it appears under in the field list and in every field picker. Pick an existing category or type a new one.
5. Pick the Data type the dimension produces: Text, Number, Country, or Boolean. This is the type of the values your rules assign, not of the field they read.
6. Switch on Show column by default in new explorer views to have it appear in new data explorer views without being added by hand.
7. Select Save. SEINō opens the new field so you can add its rules.

Add your rules

Each rule tests one field and assigns one result, under Custom rules on the field’s page.

1. Select Add rule.
2. Under If, pick the field to test, pick a condition, and enter the value to test against.
3. Under Then, enter the result to assign. It has to match the dimension’s own data type: a number for Number, a country for Country.
4. Select Save on the rule, and add the next one.

Which conditions you’re offered depends on the field you’re testing, not on the data type of the dimension you’re building.

Field you test	Conditions offered
Text	Equals, Not equals, Contains, Not contains, Starts with, Ends with, Is empty, Is not empty
Number	Equals, Not equals, Greater than, Greater than or equal to, Less than, Less than or equal to, Is empty, Is not empty
Country, true/false	Equals, Is empty, Is not empty

Is empty and Is not empty take no value, so the value box disappears when you pick one.

SEINō reads the rules from the top and stops at the first match, so put the most specific rules first. Drag a rule by its handle to move it. A rule that duplicates one above it is flagged, and a dimension needs at least one rule before it can be saved.

Set a default value

The ELSE row at the bottom of the rules catches every row no rule matched. Until you set it, the row reads No default value and unmatched rows come back empty.

Select the ELSE row, enter a value in Configure default value, and select Save. A default like Other or Uncategorized makes the gap visible in a report instead of hiding it in blanks. To clear it again, select the trash icon on the row.

Save your changes

Saving happens twice, and the second one is the one that counts.

1. Select Save in the field’s toolbar. This commits your edit inside the editor.
2. Select Save at the top of the dataset list. This writes the change to the workspace.

Until you do, Unsaved changes stays above the dataset list, and leaving for another dataset asks you to confirm. If Save is unavailable, a field still has an error: a missing category, or a rule with no result. Hover the info icon beside it to see what’s blocking you. Discard at either level rolls back to the last saved state.

Check the result

Open the data explorer on the same dataset and group by your new dimension. Every rule that fires shows as its own row, and the default catches the rest.

The size of the default group is the number to read. If it’s larger than you expected, a rule is missing or written too narrowly. If a category you expected is missing entirely, a broader rule above it is catching those rows first. SEINō calculates the dimension when the report runs, so it covers your full history straight away and any fix shows up on the next run.

Change or remove a dimension

Select the dimension in the field list to reopen it. Editing a rule, adding one, or changing the default follows the same two saves as before.

To delete it, select the trash icon in the field’s toolbar. If other custom fields have rules that read this one, SEINō lists them and warns that those rules go too. Confirm, then save the dataset.

Caution

SEINō recognises a custom dimension by its name, so renaming one creates a different field. Other custom fields whose rules read it are updated for you, but nothing outside the data model is: dashboards lose it, filters set on it stop applying without warning, and alerts and target plans that use it stop running. Rename with care once a dimension is in use.

Next: Custom fields for how dimensions, metrics, and rule order fit together.