MagicDraw/Cameo: You can easily find all elements a Stereotype has been applied to using Edit > Find OR via a Generic Table Diagram with the Stereotype as the 'Element type' (with or without sub-types).

The Generic Table Diagram approach is in some ways more more flexible than the Edit > Find dialog, since you can adapt the columns and reuse the customised diagram easily. Just assign the target Stereotype as the 'Element type:', and choose to include (or not include) sub-types.

Beware that the 'Name' column will not be immediately available as a column unless the Metatype of the targeted Stereotype is at least [NamedElement] - not just [Element) - but you can always easily add 'name' via a Custom Column anyway.

It's a good idea to always select the 'Owner' column and 'Applied Stereotype' column for display as well. Note that an Element may have more than one Stereotype applied. A handy column order is: '#', 'Owner', 'Applied Stereotype', 'Name', ...