Field does not appear in Dashboard

Hi all, I have a question. Sorry I am new here

I tried to add Workgroup field to the dashboard, but it does not appear, please refer below

What I did?

1. I add Workgroup in the GI first, and its appeared in the GI successfully

   

2. I add the Workgroup field to the rows in pivot table screen

   

3. From the pivot screen, i can see the workgroup appeared there

   

4. But using the same pivot to the dashboard, it did not appear. I tried to look for the filter but nothing seems related. What did i miss?

5. 

   Thank you in advance