Explanation
You can drag the filter by clicking on the 2 lines on top, and then dragging the filter as shown:

Explanation
Follow along:
1) Drag Assortment and Year ID (choose Discrete Month) to Columns shelf, and Sales to the Columns Shelf.
For sales, click on the pill -> choose Quick Table calculation -> Year over Year growth.
The view should now look like:

Explanation
Upon clicking on a filter, we see the following options:

Clearly, Regex Match is not one of these options!

Explanation
Tree maps size begins from maximum in top left to smallest in bottom right.

See below to learn how to create a TreeMap and add colours to it:

Explanation
When you connect to a data source, Tableau automatically separates date fields into hierarchies so you can easily break down the viz. You can also create your own custom hierarchies. For example, if you have a set of fields named Region, State, and County, you can create a hierarchy from these fields so that you can quickly drill down between levels in the viz.