class ActiveAdmin::DSL

end
end
]
link_to('my piece', '/my/link/to/piece')
[
breadcrumb do

ActiveAdmin.register Post do
Example:

Block must return an array if you want to rewrite breadcrumb links.
Block will be executed inside controller.
Rewrite breadcrumb links.

def breadcrumb(&block)
  config.breadcrumb = block
end