How to Add Third Dimension in Google Analytics

Trying to view more than two dimensions in a standard Google Analytics report can feel like hitting a wall. You can easily see your traffic by Source / Medium and add Landing Page as a secondary dimension, but what if you want to also see the breakdown by Device Category? This article will show you a few practical ways to slice your data by a third dimension in Google Analytics to uncover deeper, more meaningful insights.

Why a Third Dimension Matters

Analyzing data in just one or two dimensions is useful, but it often leaves an incomplete picture. You might know that your Google organic search traffic has a high conversion rate, but do you know if that performance is driven by mobile users or desktop users? Or maybe a specific email campaign drove a lot of sessions to your new blog post, but was it from new users or returning ones?

Adding a third dimension lets you connect the dots and answer these more nuanced questions. It moves you from high-level observation to granular analysis, which is where the real opportunities for optimization are found. Instead of just knowing what happened, you start to understand why it happened and for which specific audience segment.

Method 1: The Secondary Dimension "Filter Trick"

This is the quickest way to get a three-dimension view within any standard report, without having to build anything custom. It works by combining a primary dimension, a secondary dimension, and the report’s filter bar to act as your third dimension.

Let's use a common scenario: You want to see which landing pages are performing best for your Google organic traffic, broken down by device type.

Here’s how you do it:

Navigate to the report you want to analyze. For this example, let's go to Acquisition → All Traffic → Source / Medium. This gives you your first dimension.
Use the search bar at the top of the data table to filter for the value you want to isolate. We'll type in google / organic and hit enter. Now, the entire report is focused only on traffic from that specific source/medium. This filter has effectively become our first dimensional layer.
Next, click the Secondary Dimension dropdown button just above the table.
Search for and select Landing Page. This will be our second dimension.
Finally, click the Secondary Dimension dropdown again. This time, search for and select Device Category.

Voilà! The table now shows you a view that is locked onto "google / organic" traffic, displaying a combination of Landing Page and Device Category that drove sessions and conversions. Your three dimensions are:

Dimension 1 (by filter): Source / Medium (specifically 'google / organic')
Dimension 2 (primary): Landing Page
Dimension 3 (secondary): Device Category

This technique is fast and works in nearly any standard GA report. The main limitation is that it's tough to compare multiple values from your first dimension (like comparing google / organic vs. bing / organic) without repeatedly changing the filter.

Method 2: Building a Custom Report for True Three-Dimension Analysis

When you need a durable, shareable report that's designed from the ground up for three dimensions, custom reports are the answer. This method is far more powerful and flexible than the filter trick.

Let's say a marketing manager wants to know how different content categories are performing based on the channel that brought the user and whether the user was new or returning. This report needs to see Page Grouping → Default Channel Grouping → User Type.

Step-by-Step Guide to Creating the Custom Report:

In the left-hand navigation pane, go to Customization → Custom Reports.
Click the + New Custom Report button.
General Information: Give your report a descriptive title, like "Content Performance by Channel & User Type."
Report Content Tab: This is where the magic happens.
- Metrics: First, add the metrics you care about. These are the numbers you want to measure. Let's add Sessions, Bounce Rate, and Goal Conversions. Click the + add metric button to select each one.
- Dimension Drilldowns: This is where you'll add your three dimensions in the order you want to analyze them. Click + add dimension and select your first dimension. For our example, let's use a custom content grouping called Content Category.
- Now, add your second dimension. We'll use Default Channel Grouping.
- Finally, add your third dimension: User Type.
Filters (Optional): If you want to limit the report to only include certain data (e.g., traffic from a specific country), you can add a filter here. We'll leave it blank for now.
Click the Save button at the bottom.

How to Use Your New Report

Once you save, Google Analytics will display your new custom report. Initially, you'll only see your first dimension (Content Category). To see the second dimension, simply click on one of the category names in the list (e.g., click on "Blog Posts").

The report will "drill down," showing you the breakdown by your second dimension (Default Channel Grouping) only for Blog Posts. From there, you can click on a specific channel (e.g., "Organic Search") to drill down further and see the breakdown by your third dimension (User Type).

This method provides a clean, repeatable way to view nested relationships between three - or even four or five - dimensions.

Method 3: Using Segments as a Pseudo-Dimension

Segments are another incredibly powerful tool in Google Analytics that can function as a layer for your analysis, essentially acting as an overarching third dimension for any standard report.

A segment is a subset of your data. For example, you can create segments for "Mobile Traffic," "Traffic from the US," "Users who made a purchase," and so on. When you apply a segment, every report in GA will only show you data that matches the criteria of that segment.

Here’s how you can use a segment to achieve a three-dimension view:

In any report, click on the + Add Segment option at the top of the page.
Click the red + New Segment button.
Let's create a segment for "Canada traffic, on desktop".
- Give the segment a name, like "CA - Desktop Users".
- Under Demographics, set the Location → Country to "exactly matches" Canada.
- Under Technology, set the Device Category to "exactly matches" desktop.
Click Save.

Now, your "CA - Desktop Users" segment is applied to your report. You can navigate to any standard report — for example, the Acquisition → Source / Medium report — and add a secondary dimension like Campaign. The data you're seeing has three layers of context:

Dimension 1 (from segment): Country (Canada)
Dimension 2 (from segment): Device Category (Desktop)
Dimension 3 (primary report dimension): Source / Medium
Dimension 4 (secondary report dimension): Campaign

As you can see, this is actually giving you a four-dimension view! The beauty of segments is that you can apply them globally and quickly flip between different segments to compare performance across different audiences.

Choosing the Right Method

Use the filter trick for quick, on-the-fly analysis when you're exploring data in a standard report.
Build a custom report when you have a specific, recurring question that requires three or more dimensions. This is the cleanest and most scalable option.
Leverage segments when you want to analyze the behavior of a specific user group or traffic cohort across all of your standard reports.

Final Thoughts

Learning how to add a third dimension is a simple way to go beyond surface-level metrics and truly understand the drivers of your website's performance. Whether you use the quick filter trick, a structured custom report, or a flexible segment, layering your data gives you the context needed to make smarter, more informed decisions about your marketing and user experience.

While an amazing tool, you can see how even a seemingly simple question in Google Analytics requires multiple steps, clicks, filters, and report configurations. We built Graphed to remove this friction completely. Instead of building a custom report with three drill-downs, you can just ask in plain language, "what was our traffic by source, landing page, and device last month?" Graphed creates the chart for you instantly, allowing you to ask follow-up questions and get the insights you need in seconds, not minutes.