I cant' add a calculated field into data blend or combination

[markosci]

When working with a blended data source in Looker Studio, there is no option to add a calculated field directly inside the blend, neither during its creation nor when editing it afterward. This makes it impossible to define shared fields (such as a unified “Source” dimension) that can be used globally across charts.

Creating the calculated field at the chart level has been tested, but this approach does not solve the issue because:

• The field is not globally available as a dimension.

• It cannot be reused in other formulas.

• It cannot be used in filters or controls that require dimensions at the blend level.

In addition, the official Looker Studio documentation indicates that a button to add custom fields should be available when creating or editing a blended data source. However, in practice, this button does not appear in the blend editor.

I made a screenshoot with the properties that I can see:

[Sichali1]

Hi,

I recently answered a question that’s really similar to what you’re asking. I shared some steps and examples that might help you get the results you’re looking for. You can check it out using the link below.

If it doesn’t quite solve your problem, no worries, we can look at your exact situation and try to recreate it together. That way, we can figure out the best way to get the output you want. Let me know how it goes!

https://www.googlecloudcommunity.com/gc/Looker-Studio/Blending-data/m-p/891990#M8559

[markosci]

Thanks for your reply @Sichali1  but is not exactly what I need.

My idea is as follows:

I have several data sources and I would like to have a drop-down at the top so that in my report I can choose which data I want to see. Here is an example:

• Analytics Company 1 
• Analytics Company 2

I create an Origin field for both with their corresponding value "Company1" and "Company2". And I would like to create a dropdown to be able to filter by this Origin.

The problem is that Looker doesn't allow me to have this field calculated within the combination of both analytics to be able to use it in other elements as a filter.

Is there a better way to do this idea?

[Sichali1]

Hi,
Here's another try at answering your question and finding the best solution. I’ve come up with two possible ways to solve the problem:
Option 1: Join the Data at the Source
One way to make your filter work properly in Looker Studio is by making sure all your data comes from the same source. This means the data for both Analytics Company 1 and Analytics Company 2 should be stored in one combined dataset.
Here’s why this matters:
Looker Studio filters work by hiding or showing rows of data based on the condition you set. So, if you apply a filter to show only Analytics Company 1, Looker Studio will hide all rows that don’t belong to that company. If your data comes from two separate sources, the filter won’t work properly because it can only filter data from one source at a time.
Now, you can’t create a join using a calculated field in Looker Studio. But you can use Data Blending, which lets you combine data from up to 5 different sources.
If you’re using BigQuery, you’re not limited to 5 sources, you can join as many as needed directly in your query.
If you’re using Google Sheets, you can use Apps Script to join data in the background before sending it to Looker Studio.
In short: If you want your filters to work the way you described, it’s best to prepare your data ahead of time and make sure everything is in one data source.
Option 2: Use Buttons to Switch Between Pages
This is a more visual solution. Instead of combining data into one source, you create separate pages in your report:
One page for Analytics Company 1
Another for Analytics Company 2
Then, you use buttons (or tabs) to switch between pages. Each page shows charts and data for just one company. If you keep things like the title, layout, or background the same on each page, users may not even realize they’re switching between different report pages.
Let me know which option works best for your case, and I can help build some sample charts based on that method.

Thanks!

[markosci]

I am thinking about another alternative following what you have told me.

I am going to put a data control to select the analytics, because after several tests I have seen that the idea I had is impossible.

Although I have another idea: I have added several result cards and tried that these are not affected by the selection of the analytics that is made... is this possible?

I have tried to group those cards with a Data Control (let's call it control-b and the main one that would change all the charts of the report control-a) leaving the default selection checked but if I change in control-a, the selection of control-b is changed.

With an example:
I have as data sources the analytics of company 1, company 2 and company 3.
In Control-a I select company 2 and I would like to leave the default in control-b so that the result cards show those of company 1, company 2 and company 3.