Show items allways when blank

Hello,

I have the following issue:
I have a bar graph showing data per month. It is possible to add comments to the data with powerapps. These comments are shown in the tooltip and linked to the commented month + the application the comment was about.

I send the list of filtered applications to powerapps and save a comment for each and everyone of them. Except when someone did not select any application (in that case the visual shows all applications) but it is saved as NULL. 

Now i load in the data and would like to make it that when people filter on one application the tooltip shows the selected application (which is standard the case) + all comments with the application NULL. Because that comment is for every application.

I hope this is enough info,

Regard,

Eric.