Acumatica Dashboard Parameters
You can now do this in Acumatica 2018 which just launched the first preview version, build 18.091.0090.
You can set parameters on the Dashboards (SM208600) screen like this:
When you add the parameters to the area shown in the screenshot above, they will appear on the top of the Dashboard like this (I only added one, but you could add many parameters):
Then you decide in each Dashboard Widget whether or not to include a parameter in the filter:
Note in the screenshot above that you can now do on-they-fly filters instead of having to create Shared filters in your generic inquiries which is nice. In the past, I was cluttering up the Shared filters in my generic inquiries just for dashboards which was kind of a pain.