Filters within the sheet is something on our roadmap - don't have it just yet. But! You can use our visual Query Builder to let less technical users change the underlying data that your charts + tables are pulling from.

In terms of exporting the data, you can export to a CSV but typically you don't need to do this step to debug something. The biggest difference from Tableau is we are actually a full featured spreadsheet. You can do any investigation you want to do within Equals itself. When we want to go deeper on some dashboard we tend to make a copy of the document in Equals and dig in from there.