You simply select the items you want to nest and type Option + C. They then collapes into a single unit and appear as a sequence inside your timeline and Browser. If you want to use these as a “template”, you’ll have to Duplicate the nest, then change the items inside the nest, such as new names, etc. Do not Copy/Paste them, duplicate them–or else ALL your nests change.
Personally, I build lower thirds using cropped color mattes and Title 3D–then nest them. I like to be able to have a drop shadow playing onto the color matte.
Hopefully, this makes sense to you. Otherwise, you might try reading up on nesting in the manual. I also wrote a book which explains it succinctly.
Kevin Monahan
Author – Motion Graphics and Effects in Final Cut Pro
fcpworld.com