I am using Sample Superstore to simulate your use case.
First I am creating a simple calculated field to pick the customers I want to show as buttons:
IF [Customer Name] = "Aaron Bergman" THEN [Customer Name]
ELSEIF [Customer Name] = "Aaron Hawkins" THEN [Customer Name]
ELSEIF [Customer Name] = "Aaron Smayling" THEN [Customer Name]
ELSEIF [Customer Name] = "Adam Bellavance" THEN [Customer Name]
Then pick [Selected Customers] and add to Columns
Next, right click the Null and select Hide.
Now add the Selected Customers field also to Text.
Right click the table headers and untick Show Header.
Now it is just a matter of formatting. You can add grid lines to complete your buttons and you should end with something like this:
You can now drag these buttons to a dashboard and create a dashboard action that filters the other sheets in the dashboard once these buttons are clicked (Selected).
Here is the dashboard I created to test this solution:
A click on each name will change the bars:
I am sending you the workbook so you can check how this works at the end.
I hope this helps you!
Dashboard-Buttons.twbx 1.2 MB