The 'right' name is Un-Pivot :-)
This is a kind of data transformation that transpose columns into rows.
In Tableau there is the Pivot option available for some (not all) data sources.
But it couldn't apply in your case, because Tableau can do (Pivot) only one set of columns,
and you need it to apply twice (or more) -- for both Products and Qtds (or other metrics as well).
The Un-Pivot is logically equivalent to UNIONing your datasource table (twice or more)
and Aligning the respective Columns into a single one(s) via simple calculation(s).
Please find the attached as an example of the latter approach.
Hope it could help.
BTW, you can make two (or more) consecutive Un-Pivot steps in a Tableau Prep flow.
Un-Pivot_v10.2_YF.twbx 34.6 KB