New Power App builder here. I'm attempting to create a document approval app. In this I would like to have multiple galleries that only show documents that are in a stage or approval. I created a drop down list with the following choices in SharePoint:

I would like one gallery to only show 'First Approval', then another for 'Second Approval', etc. When I attempted to create the filter, it failed:

I created a dummy column that I inserted #s in to see if I had the write line of thought. This worked.

However I need it to function on the drop down menu for functionality, as I don't want the users to have to type in the selection. I'm assuming that I am not utilizing the Filter function correctly with the drop down menu. If Search( is a better option, that is fine as well! I don't need the galleries to be selectable, but only show the documents that have a specific Approval status. The columns is called 'ApprovalStatus'. In SharePoint its actual name is: Approval_x0020_Status. I'm not sure if that would effect the line of code.
BONUS!: Can I sort the output by dates, oldest at the top, newest at the bottom. The column is the default 'Created'.
Thank you!